BASELINE: Update Chromium to 94.0.4606.111

Change-Id: I924781584def20fc800bedf6ff41fdb96c438193 Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
author: Allan Sandfeld Jensen <allan.jensen@qt.io> 2021-10-26 13:57:00 +0200
committer: Allan Sandfeld Jensen <allan.jensen@qt.io> 2021-11-02 11:31:01 +0000
commit: 1943b3c2a1dcee36c233724fc4ee7613d71b9cf6 (patch)
tree: 8c1b5f12357025c197da5427ae02cfdc2f3570d6 /chromium/third_party/abseil-cpp
parent: 21ba0c5d4bf8fba15dddd97cd693bad2358b77fd (diff)
download: qtwebengine-chromium-1943b3c2a1dcee36c233724fc4ee7613d71b9cf6.tar.gz
149 files changed, 9018 insertions, 1568 deletions
diff --git a/chromium/third_party/abseil-cpp/BUILD.gn b/chromium/third_party/abseil-cpp/BUILD.gn
index fa2b2ad8015..c0b47158d1f 100644
--- a/chromium/third_party/abseil-cpp/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/BUILD.gn
@@ -188,12 +188,17 @@ if (build_with_chromium) {
         "absl/container:inlined_vector_test",
         "absl/memory:memory_test",
         "absl/meta:type_traits_test",
+        "absl/status:statusor_test",
         "absl/strings:ascii_test",
+        "absl/strings:cord_rep_btree_test",
+        "absl/strings:cord_rep_btree_reader_test",
+        "absl/strings:cord_rep_consume_test",
         "absl/strings:cordz_functions_test",
         "absl/strings:cordz_info_statistics_test",
         "absl/strings:cordz_info_test",
         "absl/strings:cordz_test",
         "absl/strings:cordz_update_scope_test",
+        "absl/strings:cord_rep_btree_navigator_test",
         "absl/strings:cordz_update_tracker_test",
         "absl/strings:match_test",
         "absl/strings:str_replace_test",
diff --git a/chromium/third_party/abseil-cpp/CMake/AbseilDll.cmake b/chromium/third_party/abseil-cpp/CMake/AbseilDll.cmake
index 8ee4120f691..8bdf5a504d1 100644
--- a/chromium/third_party/abseil-cpp/CMake/AbseilDll.cmake
+++ b/chromium/third_party/abseil-cpp/CMake/AbseilDll.cmake
@@ -203,6 +203,14 @@ set(ABSL_INTERNAL_DLL_FILES
   "strings/internal/charconv_parse.h"
   "strings/internal/cord_internal.cc"
   "strings/internal/cord_internal.h"
+  "strings/internal/cord_rep_consume.h"
+  "strings/internal/cord_rep_consume.cc"
+  "strings/internal/cord_rep_btree.cc"
+  "strings/internal/cord_rep_btree.h"
+  "strings/internal/cord_rep_btree_navigator.cc"
+  "strings/internal/cord_rep_btree_navigator.h"
+  "strings/internal/cord_rep_btree_reader.cc"
+  "strings/internal/cord_rep_btree_reader.h"
   "strings/internal/cord_rep_flat.h"
   "strings/internal/cord_rep_ring.cc"
   "strings/internal/cord_rep_ring.h"
diff --git a/chromium/third_party/abseil-cpp/CMake/AbseilHelpers.cmake b/chromium/third_party/abseil-cpp/CMake/AbseilHelpers.cmake
index 1a80b5b463f..17c4f4499c8 100644
--- a/chromium/third_party/abseil-cpp/CMake/AbseilHelpers.cmake
+++ b/chromium/third_party/abseil-cpp/CMake/AbseilHelpers.cmake
@@ -171,8 +171,8 @@ function(absl_cc_library)
       FILE(GENERATE OUTPUT "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc" CONTENT "\
 prefix=${CMAKE_INSTALL_PREFIX}\n\
 exec_prefix=\${prefix}\n\
-libdir=\${prefix}/${CMAKE_INSTALL_LIBDIR}\n\
-includedir=\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}\n\
+libdir=${CMAKE_INSTALL_FULL_LIBDIR}\n\
+includedir=${CMAKE_INSTALL_FULL_INCLUDEDIR}\n\
 \n\
 Name: absl_${_NAME}\n\
 Description: Abseil ${_NAME} library\n\
@@ -254,9 +254,23 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
       set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/internal)
     endif()
 
-    # INTERFACE libraries can't have the CXX_STANDARD property set
-    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
-    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
+    if(ABSL_PROPAGATE_CXX_STD)
+      # Abseil libraries require C++11 as the current minimum standard.
+      # Top-level application CMake projects should ensure a consistent C++
+      # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
+      target_compile_features(${_NAME} PUBLIC cxx_std_11)
+    else()
+      # Note: This is legacy (before CMake 3.8) behavior. Setting the
+      # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
+      # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
+      # that is the default value anyway.
+      #
+      # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
+      # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
+      # "decaying" to an older standard if the requested one isn't available).
+      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
+      set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
+    endif()
 
     # When being installed, we lose the absl_ prefix.  We want to put it back
     # to have properly named lib files.  This is a no-op when we are not being
@@ -287,6 +301,16 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
         ${ABSL_DEFAULT_LINKOPTS}
     )
     target_compile_definitions(${_NAME} INTERFACE ${ABSL_CC_LIB_DEFINES})
+
+    if(ABSL_PROPAGATE_CXX_STD)
+      # Abseil libraries require C++11 as the current minimum standard.
+      # Top-level application CMake projects should ensure a consistent C++
+      # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
+      target_compile_features(${_NAME} INTERFACE cxx_std_11)
+
+      # (INTERFACE libraries can't have the CXX_STANDARD property set, so there
+      # is no legacy behavior else case).
+    endif()
   endif()
 
   # TODO currently we don't install googletest alongside abseil sources, so
@@ -336,8 +360,8 @@ endfunction()
 #     "awesome_test.cc"
 #   DEPS
 #     absl::awesome
-#     gmock
-#     gtest_main
+#     GTest::gmock
+#     GTest::gtest_main
 # )
 function(absl_cc_test)
   if(NOT BUILD_TESTING)
@@ -390,8 +414,23 @@ function(absl_cc_test)
   # Add all Abseil targets to a folder in the IDE for organization.
   set_property(TARGET ${_NAME} PROPERTY FOLDER ${ABSL_IDE_FOLDER}/test)
 
-  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
-  set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
+  if(ABSL_PROPAGATE_CXX_STD)
+    # Abseil libraries require C++11 as the current minimum standard.
+    # Top-level application CMake projects should ensure a consistent C++
+    # standard for all compiled sources by setting CMAKE_CXX_STANDARD.
+    target_compile_features(${_NAME} PUBLIC cxx_std_11)
+  else()
+    # Note: This is legacy (before CMake 3.8) behavior. Setting the
+    # target-level CXX_STANDARD property to ABSL_CXX_STANDARD (which is
+    # initialized by CMAKE_CXX_STANDARD) should have no real effect, since
+    # that is the default value anyway.
+    #
+    # CXX_STANDARD_REQUIRED does guard against the top-level CMake project
+    # not having enabled CMAKE_CXX_STANDARD_REQUIRED (which prevents
+    # "decaying" to an older standard if the requested one isn't available).
+    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
+    set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
+  endif()
 
   add_test(NAME ${_NAME} COMMAND ${_NAME})
 endfunction()
diff --git a/chromium/third_party/abseil-cpp/CMake/README.md b/chromium/third_party/abseil-cpp/CMake/README.md
index 5eee8171d93..f8b27e63f60 100644
--- a/chromium/third_party/abseil-cpp/CMake/README.md
+++ b/chromium/third_party/abseil-cpp/CMake/README.md
@@ -34,15 +34,16 @@ to include Abseil directly in your CMake project.
 4. Add the **absl::** target you wish to use to the
 [`target_link_libraries()`](https://cmake.org/cmake/help/latest/command/target_link_libraries.html)
 section of your executable or of your library.<br>
-Here is a short CMakeLists.txt example of a project file using Abseil.
+Here is a short CMakeLists.txt example of an application project using Abseil.
 
 ```cmake
-cmake_minimum_required(VERSION 3.5)
-project(my_project)
+cmake_minimum_required(VERSION 3.8.2)
+project(my_app_project)
 
 # Pick the C++ standard to compile with.
 # Abseil currently supports C++11, C++14, and C++17.
 set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 add_subdirectory(abseil-cpp)
 
@@ -50,6 +51,44 @@ add_executable(my_exe source.cpp)
 target_link_libraries(my_exe absl::base absl::synchronization absl::strings)
 ```
 
+Note that if you are developing a library designed for use by other clients, you
+should instead leave `CMAKE_CXX_STANDARD` unset (or only set if being built as
+the current top-level CMake project) and configure the minimum required C++
+standard at the target level. If you require a later minimum C++ standard than
+Abseil does, it's a good idea to also enforce that `CMAKE_CXX_STANDARD` (which
+will control Abseil library targets) is set to at least that minimum. For
+example:
+
+```cmake
+cmake_minimum_required(VERSION 3.8.2)
+project(my_lib_project)
+
+# Leave C++ standard up to the root application, so set it only if this is the
+# current top-level CMake project.
+if(CMAKE_SOURCE_DIR STREQUAL my_lib_project_SOURCE_DIR)
+  set(CMAKE_CXX_STANDARD 17)
+  set(CMAKE_CXX_STANDARD_REQUIRED ON)
+endif()
+
+add_subdirectory(abseil-cpp)
+
+add_library(my_lib source.cpp)
+target_link_libraries(my_lib absl::base absl::synchronization absl::strings)
+
+# Enforce that my_lib requires C++17. Important to document for clients that they
+# must set CMAKE_CXX_STANDARD to 17 or higher for proper Abseil ABI compatibility
+# (since otherwise, Abseil library targets could be compiled with a lower C++
+# standard than my_lib).
+target_compile_features(my_lib PUBLIC cxx_std_17)
+if(CMAKE_CXX_STANDARD LESS 17)
+  message(FATAL_ERROR
+      "my_lib_project requires CMAKE_CXX_STANDARD >= 17 (got: ${CMAKE_CXX_STANDARD})")
+endif()
+```
+
+Then the top-level application project that uses your library is responsible for
+setting a consistent `CMAKE_CXX_STANDARD` that is sufficiently high.
+
 ### Running Abseil Tests with CMake
 
 Use the `-DBUILD_TESTING=ON` flag to run Abseil tests.
@@ -99,3 +138,48 @@ absl::synchronization
 absl::time
 absl::utility
 ```
+
+## Traditional CMake Set-Up
+
+For larger projects, it may make sense to use the traditional CMake set-up where you build and install projects separately.
+
+First, you'd need to build and install Google Test:
+```
+cmake -S /source/googletest -B /build/googletest -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/installation/dir -DBUILD_GMOCK=ON
+cmake --build /build/googletest --target install
+```
+
+Then you need to configure and build Abseil. Make sure you enable `ABSL_USE_EXTERNAL_GOOGLETEST` and `ABSL_FIND_GOOGLETEST`. You also need to enable `ABSL_ENABLE_INSTALL` so that you can install Abseil itself.
+```
+cmake -S /source/abseil-cpp -B /build/abseil-cpp -DCMAKE_PREFIX_PATH=/installation/dir -DCMAKE_INSTALL_PREFIX=/installation/dir -DABSL_ENABLE_INSTALL=ON -DABSL_USE_EXTERNAL_GOOGLETEST=ON -DABSL_FIND_GOOGLETEST=ON
+cmake --build /temporary/build/abseil-cpp
+```
+
+(`CMAKE_PREFIX_PATH` is where you already have Google Test installed; `CMAKE_INSTALL_PREFIX` is where you want to have Abseil installed; they can be different.)
+
+Run the tests:
+```
+ctest --test-dir /temporary/build/abseil-cpp
+```
+
+And finally install:
+```
+cmake --build /temporary/build/abseil-cpp --target install
+```
+
+# CMake Option Synposis
+
+## Enable Standard CMake Installation
+
+`-DABSL_ENABLE_INSTALL=ON`
+
+## Google Test Options
+
+`-DBUILD_TESTING=ON` must be set to enable testing
+
+- Have Abseil download and build Google Test for you: `-DABSL_USE_EXTERNAL_GOOGLETEST=OFF` (default)
+  - Download and build latest Google Test: `-DABSL_USE_GOOGLETEST_HEAD=ON`
+  - Download specific Google Test version (ZIP archive): `-DABSL_GOOGLETEST_DOWNLOAD_URL=https://.../version.zip`
+  - Use Google Test from specific local directory: `-DABSL_LOCAL_GOOGLETEST_DIR=/path/to/googletest`
+- Use Google Test included elsewhere in your project: `-DABSL_USE_EXTERNAL_GOOGLETEST=ON`
+- Use standard CMake `find_package(CTest)` to find installed Google Test: `-DABSL_USE_EXTERNAL_GOOGLETEST=ON -DABSL_FIND_GOOGLETEST=ON`
diff --git a/chromium/third_party/abseil-cpp/CMake/install_test_project/CMakeLists.txt b/chromium/third_party/abseil-cpp/CMake/install_test_project/CMakeLists.txt
index 06b797e9edd..eebfe617a44 100644
--- a/chromium/third_party/abseil-cpp/CMake/install_test_project/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/CMake/install_test_project/CMakeLists.txt
@@ -18,8 +18,6 @@
 cmake_minimum_required(VERSION 3.5)
 project(absl_cmake_testing CXX)
 
-set(CMAKE_CXX_STANDARD 11)
-
 add_executable(simple simple.cc)
 
 find_package(absl REQUIRED)
diff --git a/chromium/third_party/abseil-cpp/CMake/install_test_project/test.sh b/chromium/third_party/abseil-cpp/CMake/install_test_project/test.sh
index a3d39773a15..5a78c92cd1f 100755
--- a/chromium/third_party/abseil-cpp/CMake/install_test_project/test.sh
+++ b/chromium/third_party/abseil-cpp/CMake/install_test_project/test.sh
@@ -19,10 +19,9 @@
 # Fail on any error. Treat unset variables an error. Print commands as executed.
 set -euox pipefail
 
-source ci/cmake_common.sh
-
 absl_dir=/abseil-cpp
 absl_build_dir=/buildfs
+googletest_builddir=/googletest_builddir
 project_dir="${absl_dir}"/CMake/install_test_project
 project_build_dir=/buildfs/project-build
 
@@ -31,13 +30,30 @@ if [ "${LINK_TYPE:-}" = "DYNAMIC" ]; then
   build_shared_libs="ON"
 fi
 
+# Build and install GoogleTest
+mkdir "${googletest_builddir}"
+pushd "${googletest_builddir}"
+curl -L "${ABSL_GOOGLETEST_DOWNLOAD_URL}" --output "${ABSL_GOOGLETEST_COMMIT}".zip
+unzip "${ABSL_GOOGLETEST_COMMIT}".zip
+pushd "googletest-${ABSL_GOOGLETEST_COMMIT}"
+mkdir build
+pushd build
+cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS="${build_shared_libs}" ..
+make -j $(nproc)
+make install
+ldconfig
+popd
+popd
+popd
+
 # Run the LTS transformations
 ./create_lts.py 99998877
 
-# Install Abseil
+# Build and install Abseil
 pushd "${absl_build_dir}"
 cmake "${absl_dir}" \
-  -DABSL_GOOGLETEST_DOWNLOAD_URL="${ABSL_GOOGLETEST_DOWNLOAD_URL}" \
+  -DABSL_USE_EXTERNAL_GOOGLETEST=ON \
+  -DABSL_FIND_GOOGLETEST=ON  \
   -DCMAKE_BUILD_TYPE=Release \
   -DBUILD_TESTING=ON \
   -DBUILD_SHARED_LIBS="${build_shared_libs}"
diff --git a/chromium/third_party/abseil-cpp/CMakeLists.txt b/chromium/third_party/abseil-cpp/CMakeLists.txt
index d0c6e6088d3..7c8bfff4c53 100644
--- a/chromium/third_party/abseil-cpp/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/CMakeLists.txt
@@ -67,6 +67,13 @@ else()
   option(ABSL_ENABLE_INSTALL "Enable install rule" ON)
 endif()
 
+option(ABSL_PROPAGATE_CXX_STD
+  "Use CMake C++ standard meta features (e.g. cxx_std_11) that propagate to targets that link to Abseil"
+  OFF)  # TODO: Default to ON for CMake 3.8 and greater.
+if((${CMAKE_VERSION} VERSION_GREATER_EQUAL 3.8) AND (NOT ABSL_PROPAGATE_CXX_STD))
+  message(WARNING "A future Abseil release will default ABSL_PROPAGATE_CXX_STD to ON for CMake 3.8 and up. We recommend enabling this option to ensure your project still builds correctly.")
+endif()
+
 list(APPEND CMAKE_MODULE_PATH
   ${CMAKE_CURRENT_LIST_DIR}/CMake
   ${CMAKE_CURRENT_LIST_DIR}/absl/copts
@@ -102,9 +109,18 @@ endif()
 ## pthread
 find_package(Threads REQUIRED)
 
+include(CMakeDependentOption)
+
 option(ABSL_USE_EXTERNAL_GOOGLETEST
   "If ON, Abseil will assume that the targets for GoogleTest are already provided by the including project. This makes sense when Abseil is used with add_subproject." OFF)
 
+cmake_dependent_option(ABSL_FIND_GOOGLETEST
+  "If ON, Abseil will use find_package(GTest) rather than assuming that GoogleTest is already provided by the including project."
+  ON
+  "ABSL_USE_EXTERNAL_GOOGLETEST"
+  OFF)
+
+
 option(ABSL_USE_GOOGLETEST_HEAD
   "If ON, abseil will download HEAD from GoogleTest at config time." OFF)
 
@@ -116,7 +132,15 @@ set(ABSL_LOCAL_GOOGLETEST_DIR "/usr/src/googletest" CACHE PATH
 
 if(BUILD_TESTING)
   ## check targets
-  if (NOT ABSL_USE_EXTERNAL_GOOGLETEST)
+  if (ABSL_USE_EXTERNAL_GOOGLETEST)
+    if (ABSL_FIND_GOOGLETEST)
+      find_package(GTest REQUIRED)
+    else()
+      if (NOT TARGET gtest AND NOT TARGET GTest::gtest)
+        message(FATAL_ERROR "ABSL_USE_EXTERNAL_GOOGLETEST is ON and ABSL_FIND_GOOGLETEST is OFF, which means that the top-level project must build the Google Test project. However, the target gtest was not found.")
+      endif()
+    endif()
+  else()
     set(absl_gtest_build_dir ${CMAKE_BINARY_DIR}/googletest-build)
     if(ABSL_USE_GOOGLETEST_HEAD AND ABSL_GOOGLETEST_DOWNLOAD_URL)
       message(FATAL_ERROR "Do not set both ABSL_USE_GOOGLETEST_HEAD and ABSL_GOOGLETEST_DOWNLOAD_URL")
@@ -134,14 +158,22 @@ if(BUILD_TESTING)
     include(CMake/Googletest/DownloadGTest.cmake)
   endif()
 
-  check_target(gtest)
-  check_target(gtest_main)
-  check_target(gmock)
+  if (NOT ABSL_FIND_GOOGLETEST)
+    # When Google Test is included directly rather than through find_package, the aliases are missing.
+    add_library(GTest::gtest_main ALIAS gtest_main)
+    add_library(GTest::gtest ALIAS gtest)
+    add_library(GTest::gmock ALIAS gmock)
+  endif()
+
+  check_target(GTest::gtest)
+  check_target(GTest::gtest_main)
+  check_target(GTest::gmock)
+  check_target(GTest::gmock_main)
 
   list(APPEND ABSL_TEST_COMMON_LIBRARIES
-    gtest_main
-    gtest
-    gmock
+    GTest::gtest_main
+    GTest::gtest
+    GTest::gmock
     ${CMAKE_THREAD_LIBS_INIT}
   )
 endif()
diff --git a/chromium/third_party/abseil-cpp/FAQ.md b/chromium/third_party/abseil-cpp/FAQ.md
index 78028fc09f1..fbd92ce9757 100644
--- a/chromium/third_party/abseil-cpp/FAQ.md
+++ b/chromium/third_party/abseil-cpp/FAQ.md
@@ -27,7 +27,10 @@ compiler, there several ways to do this:
   file](https://docs.bazel.build/versions/master/guide.html#bazelrc)
 
 If you are using CMake as the build system, you'll need to add a line like
-`set(CMAKE_CXX_STANDARD 17)` to your top level `CMakeLists.txt` file. See the
+`set(CMAKE_CXX_STANDARD 17)` to your top level `CMakeLists.txt` file. If you
+are developing a library designed to be used by other clients, you should
+instead leave `CMAKE_CXX_STANDARD` unset and configure the minimum C++ standard
+required by each of your library targets via `target_compile_features`. See the
 [CMake build
 instructions](https://github.com/abseil/abseil-cpp/blob/master/CMake/README.md)
 for more information.
diff --git a/chromium/third_party/abseil-cpp/README.chromium b/chromium/third_party/abseil-cpp/README.chromium
index 5633e75496f..74d1e959a32 100644
--- a/chromium/third_party/abseil-cpp/README.chromium
+++ b/chromium/third_party/abseil-cpp/README.chromium
@@ -4,7 +4,7 @@ URL: https://github.com/abseil/abseil-cpp
 License: Apache 2.0
 License File: LICENSE
 Version: 0
-Revision: aad2c8a3966424bbaa2f26027d104d17f9c1c1ae
+Revision: 8e088c5f3c290c5ac53dd5010fd501d80b483115
 Security Critical: yes
 
 Description:
diff --git a/chromium/third_party/abseil-cpp/WORKSPACE b/chromium/third_party/abseil-cpp/WORKSPACE
index 258d23b5642..f4a5c476e1f 100644
--- a/chromium/third_party/abseil-cpp/WORKSPACE
+++ b/chromium/third_party/abseil-cpp/WORKSPACE
@@ -15,31 +15,30 @@
 #
 
 workspace(name = "com_google_absl")
+
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 # GoogleTest/GoogleMock framework. Used by most unit-tests.
 http_archive(
-    name = "com_google_googletest",
+    name = "com_google_googletest",  # 2021-07-09T13:28:13Z
+    sha256 = "12ef65654dc01ab40f6f33f9d02c04f2097d2cd9fbe48dc6001b29543583b0ad",
+    strip_prefix = "googletest-8d51ffdfab10b3fba636ae69bc03da4b54f8c235",
     # Keep this URL in sync with ABSL_GOOGLETEST_COMMIT in ci/cmake_common.sh.
-    urls = ["https://github.com/google/googletest/archive/8567b09290fe402cf01923e2131c5635b8ed851b.zip"],  # 2020-06-12T22:24:28Z
-    strip_prefix = "googletest-8567b09290fe402cf01923e2131c5635b8ed851b",
-    sha256 = "9a8a166eb6a56c7b3d7b19dc2c946fe4778fd6f21c7a12368ad3b836d8f1be48",
+    urls = ["https://github.com/google/googletest/archive/8d51ffdfab10b3fba636ae69bc03da4b54f8c235.zip"],
 )
 
 # Google benchmark.
 http_archive(
-    name = "com_github_google_benchmark",
-    urls = ["https://github.com/google/benchmark/archive/bf585a2789e30585b4e3ce6baf11ef2750b54677.zip"],  # 2020-11-26T11:14:03Z
-    strip_prefix = "benchmark-bf585a2789e30585b4e3ce6baf11ef2750b54677",
-    sha256 = "2a778d821997df7d8646c9c59b8edb9a573a6e04c534c01892a40aa524a7b68c",
+    name = "com_github_google_benchmark",  # 2021-07-01T09:02:54Z
+    sha256 = "1cb4b97a90aa1fd9c8e412a6bc29fc13fc140162a4a0db3811af40befd8c9ea5",
+    strip_prefix = "benchmark-e451e50e9b8af453f076dec10bd6890847f1624e",
+    urls = ["https://github.com/google/benchmark/archive/e451e50e9b8af453f076dec10bd6890847f1624e.zip"],
 )
 
 # C++ rules for Bazel.
 http_archive(
-    name = "rules_cc",
-    sha256 = "9a446e9dd9c1bb180c86977a8dc1e9e659550ae732ae58bd2e8fd51e15b2c91d",
-    strip_prefix = "rules_cc-262ebec3c2296296526740db4aefce68c80de7fa",
-    urls = [
-        "https://github.com/bazelbuild/rules_cc/archive/262ebec3c2296296526740db4aefce68c80de7fa.zip",
-    ],
+    name = "rules_cc",  # 2021-06-07T16:41:49Z
+    sha256 = "b295cad8c5899e371dde175079c0a2cdc0151f5127acc92366a8c986beb95c76",
+    strip_prefix = "rules_cc-daf6ace7cfeacd6a83e9ff2ed659f416537b6c74",
+    urls = ["https://github.com/bazelbuild/rules_cc/archive/daf6ace7cfeacd6a83e9ff2ed659f416537b6c74.zip"],
 )
diff --git a/chromium/third_party/abseil-cpp/absl/algorithm/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/algorithm/CMakeLists.txt
index 56cd0fb85b5..609d858946e 100644
--- a/chromium/third_party/abseil-cpp/absl/algorithm/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/algorithm/CMakeLists.txt
@@ -35,7 +35,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::algorithm
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -65,5 +65,5 @@ absl_cc_test(
     absl::core_headers
     absl::memory
     absl::span
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/algorithm/container.h b/chromium/third_party/abseil-cpp/absl/algorithm/container.h
index 1652e7b055b..c38a4a63db7 100644
--- a/chromium/third_party/abseil-cpp/absl/algorithm/container.h
+++ b/chromium/third_party/abseil-cpp/absl/algorithm/container.h
@@ -1262,7 +1262,7 @@ OutputIterator c_set_union(const C1& c1, const C2& c2, OutputIterator output,
 // c_set_intersection()
 //
 // Container-based version of the <algorithm> `std::set_intersection()` function
-// to return an iterator containing the intersection of two containers.
+// to return an iterator containing the intersection of two sorted containers.
 template <typename C1, typename C2, typename OutputIterator,
           typename = typename std::enable_if<
               !container_algorithm_internal::IsUnorderedContainer<C1>::value,
@@ -1272,6 +1272,11 @@ template <typename C1, typename C2, typename OutputIterator,
               void>::type>
 OutputIterator c_set_intersection(const C1& c1, const C2& c2,
                                   OutputIterator output) {
+  // In debug builds, ensure that both containers are sorted with respect to the
+  // default comparator. std::set_intersection requires the containers be sorted
+  // using operator<.
+  assert(absl::c_is_sorted(c1));
+  assert(absl::c_is_sorted(c2));
   return std::set_intersection(container_algorithm_internal::c_begin(c1),
                                container_algorithm_internal::c_end(c1),
                                container_algorithm_internal::c_begin(c2),
@@ -1289,6 +1294,11 @@ template <typename C1, typename C2, typename OutputIterator, typename LessThan,
               void>::type>
 OutputIterator c_set_intersection(const C1& c1, const C2& c2,
                                   OutputIterator output, LessThan&& comp) {
+  // In debug builds, ensure that both containers are sorted with respect to the
+  // default comparator. std::set_intersection requires the containers be sorted
+  // using the same comparator.
+  assert(absl::c_is_sorted(c1, comp));
+  assert(absl::c_is_sorted(c2, comp));
   return std::set_intersection(container_algorithm_internal::c_begin(c1),
                                container_algorithm_internal::c_end(c1),
                                container_algorithm_internal::c_begin(c2),
diff --git a/chromium/third_party/abseil-cpp/absl/base/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/base/CMakeLists.txt
index 981b8cc008c..7d56aa13469 100644
--- a/chromium/third_party/abseil-cpp/absl/base/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/base/CMakeLists.txt
@@ -230,7 +230,7 @@ absl_cc_library(
     ${ABSL_DEFAULT_COPTS}
   DEPS
     absl::config
-    gtest
+    GTest::gtest
   TESTONLY
 )
 
@@ -259,7 +259,7 @@ absl_cc_library(
     absl::meta
     absl::strings
     absl::utility
-    gtest
+    GTest::gtest
   TESTONLY
 )
 
@@ -273,7 +273,7 @@ absl_cc_test(
   DEPS
     absl::exception_safety_testing
     absl::memory
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -300,8 +300,8 @@ absl_cc_test(
     absl::atomic_hook_test_helper
     absl::atomic_hook
     absl::core_headers
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -314,7 +314,7 @@ absl_cc_test(
   DEPS
     absl::base
     absl::core_headers
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -327,8 +327,8 @@ absl_cc_test(
   DEPS
     absl::errno_saver
     absl::strerror
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -342,7 +342,7 @@ absl_cc_test(
     absl::base
     absl::config
     absl::throw_delegate
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -357,7 +357,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::base_internal
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -371,8 +371,8 @@ absl_cc_test(
     absl::base_internal
     absl::memory
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -388,7 +388,7 @@ absl_cc_library(
     absl::base_internal
     absl::core_headers
     absl::synchronization
-    gtest
+    GTest::gtest
   TESTONLY
 )
 
@@ -406,7 +406,7 @@ absl_cc_test(
     absl::config
     absl::core_headers
     absl::synchronization
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -435,7 +435,7 @@ absl_cc_test(
     absl::base
     absl::config
     absl::endian
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -448,7 +448,7 @@ absl_cc_test(
   DEPS
     absl::config
     absl::synchronization
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -462,7 +462,7 @@ absl_cc_test(
     absl::base
     absl::core_headers
     absl::synchronization
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -475,7 +475,7 @@ absl_cc_test(
   DEPS
     absl::raw_logging_internal
     absl::strings
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -488,7 +488,7 @@ absl_cc_test(
   DEPS
     absl::base
     absl::synchronization
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -516,7 +516,7 @@ absl_cc_test(
     absl::core_headers
     absl::synchronization
     Threads::Threads
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -543,7 +543,7 @@ absl_cc_test(
   DEPS
     absl::exponential_biased
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -570,7 +570,7 @@ absl_cc_test(
   DEPS
     absl::core_headers
     absl::periodic_sampler
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -596,7 +596,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::scoped_set_env
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -620,8 +620,8 @@ absl_cc_test(
     absl::flags_marshalling
     absl::log_severity
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -651,8 +651,8 @@ absl_cc_test(
   DEPS
     absl::strerror
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -677,7 +677,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::fast_type_id
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -690,5 +690,5 @@ absl_cc_test(
   DEPS
     absl::core_headers
     absl::optional
-    gtest_main
+    GTest::gtest_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/base/internal/exception_safety_testing.h b/chromium/third_party/abseil-cpp/absl/base/internal/exception_safety_testing.h
index 6ba89d05dfc..77a5aec6428 100644
--- a/chromium/third_party/abseil-cpp/absl/base/internal/exception_safety_testing.h
+++ b/chromium/third_party/abseil-cpp/absl/base/internal/exception_safety_testing.h
@@ -536,7 +536,22 @@ class ThrowingValue : private exceptions_internal::TrackedObject {
   }
 
   // Memory management operators
-  // Args.. allows us to overload regular and placement new in one shot
+  static void* operator new(size_t s) noexcept(
+      IsSpecified(TypeSpec::kNoThrowNew)) {
+    if (!IsSpecified(TypeSpec::kNoThrowNew)) {
+      exceptions_internal::MaybeThrow(ABSL_PRETTY_FUNCTION, true);
+    }
+    return ::operator new(s);
+  }
+
+  static void* operator new[](size_t s) noexcept(
+      IsSpecified(TypeSpec::kNoThrowNew)) {
+    if (!IsSpecified(TypeSpec::kNoThrowNew)) {
+      exceptions_internal::MaybeThrow(ABSL_PRETTY_FUNCTION, true);
+    }
+    return ::operator new[](s);
+  }
+
   template <typename... Args>
   static void* operator new(size_t s, Args&&... args) noexcept(
       IsSpecified(TypeSpec::kNoThrowNew)) {
@@ -557,12 +572,6 @@ class ThrowingValue : private exceptions_internal::TrackedObject {
 
   // Abseil doesn't support throwing overloaded operator delete.  These are
   // provided so a throwing operator-new can clean up after itself.
-  //
-  // We provide both regular and templated operator delete because if only the
-  // templated version is provided as we did with operator new, the compiler has
-  // no way of knowing which overload of operator delete to call. See
-  // https://en.cppreference.com/w/cpp/memory/new/operator_delete and
-  // https://en.cppreference.com/w/cpp/language/delete for the gory details.
   void operator delete(void* p) noexcept { ::operator delete(p); }
 
   template <typename... Args>
@@ -726,9 +735,8 @@ class ThrowingAllocator : private exceptions_internal::TrackedObject {
 
   ThrowingAllocator select_on_container_copy_construction() noexcept(
       IsSpecified(AllocSpec::kNoThrowAllocate)) {
-    auto& out = *this;
     ReadStateAndMaybeThrow(ABSL_PRETTY_FUNCTION);
-    return out;
+    return *this;
   }
 
   template <typename U>
diff --git a/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.cc b/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.cc
index 1b30c061e3b..05aeea566c8 100644
--- a/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.cc
+++ b/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.cc
@@ -64,7 +64,7 @@ int64_t ExponentialBiased::GetSkipCount(int64_t mean) {
     // Assume huge values are bias neutral, retain bias for next call.
     return std::numeric_limits<int64_t>::max() / 2;
   }
-  double value = std::round(interval);
+  double value = std::rint(interval);
   bias_ = interval - value;
   return value;
 }
diff --git a/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.h b/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.h
index 94f79a3378d..a81f10e2305 100644
--- a/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.h
+++ b/chromium/third_party/abseil-cpp/absl/base/internal/exponential_biased.h
@@ -66,7 +66,7 @@ namespace base_internal {
 // Adjusting with rounding bias is relatively trivial:
 //
 //    double value = bias_ + exponential_distribution(mean)();
-//    double rounded_value = std::round(value);
+//    double rounded_value = std::rint(value);
 //    bias_ = value - rounded_value;
 //    return rounded_value;
 //
diff --git a/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.cc b/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.cc
index 6ea010ed0d3..9950e63a794 100644
--- a/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.cc
+++ b/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.cc
@@ -120,10 +120,10 @@ void SetCurrentThreadIdentity(
     ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11
 
 // Please see the comment on `CurrentThreadIdentityIfPresent` in
-// thread_identity.h. Because DLLs cannot expose thread_local variables in
-// headers, we opt for the correct-but-slower option of placing the definition
-// of this function only in a translation unit inside DLL.
-#if defined(ABSL_BUILD_DLL) || defined(ABSL_CONSUME_DLL)
+// thread_identity.h. When we cannot expose thread_local variables in
+// headers, we opt for the correct-but-slower option of not inlining this
+// function.
+#ifndef ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT
 ThreadIdentity* CurrentThreadIdentityIfPresent() { return thread_identity_ptr; }
 #endif
 #endif
diff --git a/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.h b/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.h
index 9ee651a3a6e..659694b326e 100644
--- a/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.h
+++ b/chromium/third_party/abseil-cpp/absl/base/internal/thread_identity.h
@@ -188,25 +188,25 @@ void ClearCurrentThreadIdentity();
 // May be chosen at compile time via: -DABSL_FORCE_THREAD_IDENTITY_MODE=<mode
 // index>
 #ifdef ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC
-#error ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC cannot be direcly set
+#error ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC cannot be directly set
 #else
 #define ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC 0
 #endif
 
 #ifdef ABSL_THREAD_IDENTITY_MODE_USE_TLS
-#error ABSL_THREAD_IDENTITY_MODE_USE_TLS cannot be direcly set
+#error ABSL_THREAD_IDENTITY_MODE_USE_TLS cannot be directly set
 #else
 #define ABSL_THREAD_IDENTITY_MODE_USE_TLS 1
 #endif
 
 #ifdef ABSL_THREAD_IDENTITY_MODE_USE_CPP11
-#error ABSL_THREAD_IDENTITY_MODE_USE_CPP11 cannot be direcly set
+#error ABSL_THREAD_IDENTITY_MODE_USE_CPP11 cannot be directly set
 #else
 #define ABSL_THREAD_IDENTITY_MODE_USE_CPP11 2
 #endif
 
 #ifdef ABSL_THREAD_IDENTITY_MODE
-#error ABSL_THREAD_IDENTITY_MODE cannot be direcly set
+#error ABSL_THREAD_IDENTITY_MODE cannot be directly set
 #elif defined(ABSL_FORCE_THREAD_IDENTITY_MODE)
 #define ABSL_THREAD_IDENTITY_MODE ABSL_FORCE_THREAD_IDENTITY_MODE
 #elif defined(_WIN32) && !defined(__MINGW32__)
@@ -236,13 +236,18 @@ ABSL_CONST_INIT extern thread_local ThreadIdentity* thread_identity_ptr;
 #error Thread-local storage not detected on this platform
 #endif
 
-// thread_local variables cannot be in headers exposed by DLLs. However, it is
-// important for performance reasons in general that
-// `CurrentThreadIdentityIfPresent` be inlined. This is not possible across a
-// DLL boundary so, with DLLs, we opt to have the function not be inlined. Note
+// thread_local variables cannot be in headers exposed by DLLs or in certain
+// build configurations on Apple platforms. However, it is important for
+// performance reasons in general that `CurrentThreadIdentityIfPresent` be
+// inlined. In the other cases we opt to have the function not be inlined. Note
 // that `CurrentThreadIdentityIfPresent` is declared above so we can exclude
-// this entire inline definition when compiling as a DLL.
-#if !defined(ABSL_BUILD_DLL) && !defined(ABSL_CONSUME_DLL)
+// this entire inline definition.
+#if !defined(__APPLE__) && !defined(ABSL_BUILD_DLL) && \
+    !defined(ABSL_CONSUME_DLL)
+#define ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT 1
+#endif
+
+#ifdef ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT
 inline ThreadIdentity* CurrentThreadIdentityIfPresent() {
   return thread_identity_ptr;
 }
diff --git a/chromium/third_party/abseil-cpp/absl/cleanup/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/cleanup/CMakeLists.txt
index a2dd78a84a3..26a6d0dce3d 100644
--- a/chromium/third_party/abseil-cpp/absl/cleanup/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/cleanup/CMakeLists.txt
@@ -51,5 +51,5 @@ absl_cc_test(
     absl::cleanup
     absl::config
     absl::utility
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/cleanup/cleanup.h b/chromium/third_party/abseil-cpp/absl/cleanup/cleanup.h
index 61b53d5531a..960ccd080e0 100644
--- a/chromium/third_party/abseil-cpp/absl/cleanup/cleanup.h
+++ b/chromium/third_party/abseil-cpp/absl/cleanup/cleanup.h
@@ -86,25 +86,25 @@ class ABSL_MUST_USE_RESULT Cleanup final {
                 "Callbacks that return values are not supported.");
 
  public:
-  Cleanup(Callback callback)  // NOLINT
-      : storage_(std::move(callback), /* is_callback_engaged = */ true) {}
+  Cleanup(Callback callback) : storage_(std::move(callback)) {}  // NOLINT
 
   Cleanup(Cleanup&& other) = default;
 
   void Cancel() && {
     ABSL_HARDENING_ASSERT(storage_.IsCallbackEngaged());
-    storage_.DisengageCallback();
+    storage_.DestroyCallback();
   }
 
   void Invoke() && {
     ABSL_HARDENING_ASSERT(storage_.IsCallbackEngaged());
-    storage_.DisengageCallback();
     storage_.InvokeCallback();
+    storage_.DestroyCallback();
   }
 
   ~Cleanup() {
     if (storage_.IsCallbackEngaged()) {
       storage_.InvokeCallback();
+      storage_.DestroyCallback();
     }
   }
 
diff --git a/chromium/third_party/abseil-cpp/absl/cleanup/cleanup_test.cc b/chromium/third_party/abseil-cpp/absl/cleanup/cleanup_test.cc
index 792595d6cd8..46b885899cd 100644
--- a/chromium/third_party/abseil-cpp/absl/cleanup/cleanup_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/cleanup/cleanup_test.cc
@@ -264,4 +264,48 @@ TYPED_TEST(CleanupTest, Move) {
   EXPECT_FALSE(called);  // Destructor shouldn't invoke the callback
 }
 
+int DestructionCount = 0;
+
+struct DestructionCounter {
+  void operator()() {}
+
+  ~DestructionCounter() { ++DestructionCount; }
+};
+
+TYPED_TEST(CleanupTest, DestructorDestroys) {
+  {
+    auto cleanup =
+        absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
+    DestructionCount = 0;
+  }
+
+  EXPECT_EQ(DestructionCount, 1);  // Engaged cleanup destroys
+}
+
+TYPED_TEST(CleanupTest, CancelDestroys) {
+  {
+    auto cleanup =
+        absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
+    DestructionCount = 0;
+
+    std::move(cleanup).Cancel();
+    EXPECT_EQ(DestructionCount, 1);  // Cancel destroys
+  }
+
+  EXPECT_EQ(DestructionCount, 1);  // Canceled cleanup does not double destroy
+}
+
+TYPED_TEST(CleanupTest, InvokeDestroys) {
+  {
+    auto cleanup =
+        absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
+    DestructionCount = 0;
+
+    std::move(cleanup).Invoke();
+    EXPECT_EQ(DestructionCount, 1);  // Invoke destroys
+  }
+
+  EXPECT_EQ(DestructionCount, 1);  // Invoked cleanup does not double destroy
+}
+
 }  // namespace
diff --git a/chromium/third_party/abseil-cpp/absl/cleanup/internal/cleanup.h b/chromium/third_party/abseil-cpp/absl/cleanup/internal/cleanup.h
index b4c40737472..2783fcb7c16 100644
--- a/chromium/third_party/abseil-cpp/absl/cleanup/internal/cleanup.h
+++ b/chromium/third_party/abseil-cpp/absl/cleanup/internal/cleanup.h
@@ -15,10 +15,12 @@
 #ifndef ABSL_CLEANUP_INTERNAL_CLEANUP_H_
 #define ABSL_CLEANUP_INTERNAL_CLEANUP_H_
 
+#include <new>
 #include <type_traits>
 #include <utility>
 
 #include "absl/base/internal/invoke.h"
+#include "absl/base/macros.h"
 #include "absl/base/thread_annotations.h"
 #include "absl/utility/utility.h"
 
@@ -45,14 +47,22 @@ class Storage {
  public:
   Storage() = delete;
 
-  Storage(Callback callback, bool is_callback_engaged)
-      : callback_(std::move(callback)),
-        is_callback_engaged_(is_callback_engaged) {}
+  explicit Storage(Callback callback) {
+    // Placement-new into a character buffer is used for eager destruction when
+    // the cleanup is invoked or cancelled. To ensure this optimizes well, the
+    // behavior is implemented locally instead of using an absl::optional.
+    ::new (GetCallbackBuffer()) Callback(std::move(callback));
+    is_callback_engaged_ = true;
+  }
+
+  Storage(Storage&& other) {
+    ABSL_HARDENING_ASSERT(other.IsCallbackEngaged());
 
-  Storage(Storage&& other)
-      : callback_(std::move(other.callback_)),
-        is_callback_engaged_(
-            absl::exchange(other.is_callback_engaged_, false)) {}
+    ::new (GetCallbackBuffer()) Callback(std::move(other.GetCallback()));
+    is_callback_engaged_ = true;
+
+    other.DestroyCallback();
+  }
 
   Storage(const Storage& other) = delete;
 
@@ -60,17 +70,26 @@ class Storage {
 
   Storage& operator=(const Storage& other) = delete;
 
+  void* GetCallbackBuffer() { return static_cast<void*>(+callback_buffer_); }
+
+  Callback& GetCallback() {
+    return *reinterpret_cast<Callback*>(GetCallbackBuffer());
+  }
+
   bool IsCallbackEngaged() const { return is_callback_engaged_; }
 
-  void DisengageCallback() { is_callback_engaged_ = false; }
+  void DestroyCallback() {
+    is_callback_engaged_ = false;
+    GetCallback().~Callback();
+  }
 
   void InvokeCallback() ABSL_NO_THREAD_SAFETY_ANALYSIS {
-    std::move(callback_)();
+    std::move(GetCallback())();
   }
 
  private:
-  Callback callback_;
   bool is_callback_engaged_;
+  alignas(Callback) char callback_buffer_[sizeof(Callback)];
 };
 
 }  // namespace cleanup_internal
diff --git a/chromium/third_party/abseil-cpp/absl/container/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/container/CMakeLists.txt
index 2d7d0e65f25..91c4015437d 100644
--- a/chromium/third_party/abseil-cpp/absl/container/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/container/CMakeLists.txt
@@ -80,7 +80,7 @@ absl_cc_test(
     absl::strings
     absl::test_instance_tracker
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -109,7 +109,7 @@ absl_cc_test(
     absl::optional
     absl::test_instance_tracker
     absl::utility
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -144,7 +144,7 @@ absl_cc_test(
     absl::exception_testing
     absl::hash_testing
     absl::memory
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -158,7 +158,7 @@ absl_cc_test(
     absl::fixed_array
     absl::config
     absl::exception_safety_testing
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -222,7 +222,7 @@ absl_cc_test(
     absl::memory
     absl::raw_logging_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -236,7 +236,7 @@ absl_cc_test(
     absl::inlined_vector
     absl::config
     absl::exception_safety_testing
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -262,7 +262,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::test_instance_tracker
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -297,7 +297,7 @@ absl_cc_test(
     absl::unordered_map_modifiers_test
     absl::any
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -335,7 +335,7 @@ absl_cc_test(
     absl::memory
     absl::raw_logging_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -370,7 +370,7 @@ absl_cc_test(
     absl::unordered_map_lookup_test
     absl::unordered_map_members_test
     absl::unordered_map_modifiers_test
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -404,7 +404,7 @@ absl_cc_test(
     absl::unordered_set_lookup_test
     absl::unordered_set_members_test
     absl::unordered_set_modifiers_test
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -433,7 +433,7 @@ absl_cc_test(
     absl::container_memory
     absl::strings
     absl::test_instance_tracker
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -465,7 +465,7 @@ absl_cc_test(
     absl::hash
     absl::random_random
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -507,7 +507,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::hash_policy_testing
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -531,7 +531,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::hash_policy_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -561,7 +561,7 @@ absl_cc_test(
   DEPS
     absl::hashtablez_sampler
     absl::have_sse
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -618,7 +618,7 @@ absl_cc_test(
   DEPS
     absl::hash_policy_traits
     absl::node_hash_policy
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -693,7 +693,7 @@ absl_cc_test(
     absl::core_headers
     absl::raw_logging_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -707,7 +707,7 @@ absl_cc_test(
     absl::raw_hash_set
     absl::tracked
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -740,7 +740,7 @@ absl_cc_test(
     absl::core_headers
     absl::raw_logging_internal
     absl::span
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -765,7 +765,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -779,7 +779,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -792,7 +792,7 @@ absl_cc_library(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::type_traits
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -806,7 +806,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -820,7 +820,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -834,7 +834,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -847,7 +847,7 @@ absl_cc_library(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::type_traits
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -861,7 +861,7 @@ absl_cc_library(
   DEPS
     absl::hash_generator_testing
     absl::hash_policy_testing
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -877,7 +877,7 @@ absl_cc_test(
     absl::unordered_set_lookup_test
     absl::unordered_set_members_test
     absl::unordered_set_modifiers_test
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -892,5 +892,5 @@ absl_cc_test(
     absl::unordered_map_lookup_test
     absl::unordered_map_members_test
     absl::unordered_map_modifiers_test
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/container/btree_test.cc b/chromium/third_party/abseil-cpp/absl/container/btree_test.cc
index 464dabac27c..d27cf271059 100644
--- a/chromium/third_party/abseil-cpp/absl/container/btree_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/container/btree_test.cc
@@ -595,7 +595,7 @@ void BtreeTest() {
   using V = typename remove_pair_const<typename T::value_type>::type;
   const std::vector<V> random_values = GenerateValuesWithSeed<V>(
       absl::GetFlag(FLAGS_test_values), 4 * absl::GetFlag(FLAGS_test_values),
-      testing::GTEST_FLAG(random_seed));
+      GTEST_FLAG_GET(random_seed));
 
   unique_checker<T, C> container;
 
@@ -619,7 +619,7 @@ void BtreeMultiTest() {
   using V = typename remove_pair_const<typename T::value_type>::type;
   const std::vector<V> random_values = GenerateValuesWithSeed<V>(
       absl::GetFlag(FLAGS_test_values), 4 * absl::GetFlag(FLAGS_test_values),
-      testing::GTEST_FLAG(random_seed));
+      GTEST_FLAG_GET(random_seed));
 
   multi_checker<T, C> container;
 
@@ -1708,10 +1708,25 @@ TEST(Btree, StrSplitCompatible) {
   EXPECT_EQ(split_set, expected_set);
 }
 
-// We can't use EXPECT_EQ/etc. to compare absl::weak_ordering because they
-// convert literal 0 to int and absl::weak_ordering can only be compared with
-// literal 0. Defining this function allows for avoiding ClangTidy warnings.
-bool Identity(const bool b) { return b; }
+TEST(Btree, KeyComp) {
+  absl::btree_set<int> s;
+  EXPECT_TRUE(s.key_comp()(1, 2));
+  EXPECT_FALSE(s.key_comp()(2, 2));
+  EXPECT_FALSE(s.key_comp()(2, 1));
+
+  absl::btree_map<int, int> m1;
+  EXPECT_TRUE(m1.key_comp()(1, 2));
+  EXPECT_FALSE(m1.key_comp()(2, 2));
+  EXPECT_FALSE(m1.key_comp()(2, 1));
+
+  // Even though we internally adapt the comparator of `m2` to be three-way and
+  // heterogeneous, the comparator we expose through key_comp() is the original
+  // unadapted comparator.
+  absl::btree_map<std::string, int> m2;
+  EXPECT_TRUE(m2.key_comp()("a", "b"));
+  EXPECT_FALSE(m2.key_comp()("b", "b"));
+  EXPECT_FALSE(m2.key_comp()("b", "a"));
+}
 
 TEST(Btree, ValueComp) {
   absl::btree_set<int> s;
@@ -1724,13 +1739,13 @@ TEST(Btree, ValueComp) {
   EXPECT_FALSE(m1.value_comp()(std::make_pair(2, 0), std::make_pair(2, 0)));
   EXPECT_FALSE(m1.value_comp()(std::make_pair(2, 0), std::make_pair(1, 0)));
 
+  // Even though we internally adapt the comparator of `m2` to be three-way and
+  // heterogeneous, the comparator we expose through value_comp() is based on
+  // the original unadapted comparator.
   absl::btree_map<std::string, int> m2;
-  EXPECT_TRUE(Identity(
-      m2.value_comp()(std::make_pair("a", 0), std::make_pair("b", 0)) < 0));
-  EXPECT_TRUE(Identity(
-      m2.value_comp()(std::make_pair("b", 0), std::make_pair("b", 0)) == 0));
-  EXPECT_TRUE(Identity(
-      m2.value_comp()(std::make_pair("b", 0), std::make_pair("a", 0)) > 0));
+  EXPECT_TRUE(m2.value_comp()(std::make_pair("a", 0), std::make_pair("b", 0)));
+  EXPECT_FALSE(m2.value_comp()(std::make_pair("b", 0), std::make_pair("b", 0)));
+  EXPECT_FALSE(m2.value_comp()(std::make_pair("b", 0), std::make_pair("a", 0)));
 }
 
 TEST(Btree, DefaultConstruction) {
@@ -2906,8 +2921,7 @@ TEST(Btree, SupportsFunctionPtrComparator) {
   map[1] = 1;
   EXPECT_THAT(map, ElementsAre(Pair(1, 1)));
   EXPECT_TRUE(map.key_comp()(1, 2));
-  // TODO(ezb): support value_comp() in this case and uncomment.
-  // EXPECT_TRUE(map.value_comp()(std::make_pair(1, 1), std::make_pair(2, 2)));
+  EXPECT_TRUE(map.value_comp()(std::make_pair(1, 1), std::make_pair(2, 2)));
 }
 
 template <typename Compare>
diff --git a/chromium/third_party/abseil-cpp/absl/container/fixed_array.h b/chromium/third_party/abseil-cpp/absl/container/fixed_array.h
index fcb3e545b24..839ba0bc16d 100644
--- a/chromium/third_party/abseil-cpp/absl/container/fixed_array.h
+++ b/chromium/third_party/abseil-cpp/absl/container/fixed_array.h
@@ -73,11 +73,6 @@ constexpr static auto kFixedArrayUseDefault = static_cast<size_t>(-1);
 // uninitialized (e.g. int, int[4], double), and others default-constructed.
 // This matches the behavior of c-style arrays and `std::array`, but not
 // `std::vector`.
-//
-// Note that `FixedArray` does not provide a public allocator; if it requires a
-// heap allocation, it will do so with global `::operator new[]()` and
-// `::operator delete[]()`, even if T provides class-scope overrides for these
-// operators.
 template <typename T, size_t N = kFixedArrayUseDefault,
           typename A = std::allocator<T>>
 class FixedArray {
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/btree.h b/chromium/third_party/abseil-cpp/absl/container/internal/btree.h
index d372a1d6a24..f636c5fc73a 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/btree.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/btree.h
@@ -88,7 +88,12 @@ struct StringBtreeDefaultLess {
 
   // Compatibility constructor.
   StringBtreeDefaultLess(std::less<std::string>) {}  // NOLINT
-  StringBtreeDefaultLess(std::less<string_view>) {}  // NOLINT
+  StringBtreeDefaultLess(std::less<absl::string_view>) {}  // NOLINT
+
+  // Allow converting to std::less for use in key_comp()/value_comp().
+  explicit operator std::less<std::string>() const { return {}; }
+  explicit operator std::less<absl::string_view>() const { return {}; }
+  explicit operator std::less<absl::Cord>() const { return {}; }
 
   absl::weak_ordering operator()(absl::string_view lhs,
                                  absl::string_view rhs) const {
@@ -115,7 +120,12 @@ struct StringBtreeDefaultGreater {
   StringBtreeDefaultGreater() = default;
 
   StringBtreeDefaultGreater(std::greater<std::string>) {}  // NOLINT
-  StringBtreeDefaultGreater(std::greater<string_view>) {}  // NOLINT
+  StringBtreeDefaultGreater(std::greater<absl::string_view>) {}  // NOLINT
+
+  // Allow converting to std::greater for use in key_comp()/value_comp().
+  explicit operator std::greater<std::string>() const { return {}; }
+  explicit operator std::greater<absl::string_view>() const { return {}; }
+  explicit operator std::greater<absl::Cord>() const { return {}; }
 
   absl::weak_ordering operator()(absl::string_view lhs,
                                  absl::string_view rhs) const {
@@ -217,6 +227,8 @@ struct prefers_linear_node_search<
 template <typename Key, typename Compare, typename Alloc, int TargetNodeSize,
           bool Multi, typename SlotPolicy>
 struct common_params {
+  using original_key_compare = Compare;
+
   // If Compare is a common comparator for a string-like type, then we adapt it
   // to use heterogeneous lookup and to be a key-compare-to comparator.
   using key_compare = typename key_compare_to_adapter<Compare>::type;
@@ -317,16 +329,21 @@ struct map_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi,
   using value_type = typename super_type::value_type;
   using init_type = typename super_type::init_type;
 
-  using key_compare = typename super_type::key_compare;
-  // Inherit from key_compare for empty base class optimization.
-  struct value_compare : private key_compare {
-    value_compare() = default;
-    explicit value_compare(const key_compare &cmp) : key_compare(cmp) {}
+  using original_key_compare = typename super_type::original_key_compare;
+  // Reference: https://en.cppreference.com/w/cpp/container/map/value_compare
+  class value_compare {
+    template <typename Params>
+    friend class btree;
 
-    template <typename T, typename U>
-    auto operator()(const T &left, const U &right) const
-        -> decltype(std::declval<key_compare>()(left.first, right.first)) {
-      return key_compare::operator()(left.first, right.first);
+   protected:
+    explicit value_compare(original_key_compare c) : comp(std::move(c)) {}
+
+    original_key_compare comp;  // NOLINT
+
+   public:
+    auto operator()(const value_type &lhs, const value_type &rhs) const
+        -> decltype(comp(lhs.first, rhs.first)) {
+      return comp(lhs.first, rhs.first);
     }
   };
   using is_map_container = std::true_type;
@@ -392,7 +409,8 @@ struct set_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi,
                                   set_slot_policy<Key>> {
   using value_type = Key;
   using slot_type = typename set_params::common_params::slot_type;
-  using value_compare = typename set_params::common_params::key_compare;
+  using value_compare =
+      typename set_params::common_params::original_key_compare;
   using is_map_container = std::false_type;
 
   template <typename V>
@@ -1129,6 +1147,7 @@ class btree {
   using size_type = typename Params::size_type;
   using difference_type = typename Params::difference_type;
   using key_compare = typename Params::key_compare;
+  using original_key_compare = typename Params::original_key_compare;
   using value_compare = typename Params::value_compare;
   using allocator_type = typename Params::allocator_type;
   using reference = typename Params::reference;
@@ -1338,7 +1357,9 @@ class btree {
     return compare_internal::compare_result_as_less_than(key_comp()(a, b));
   }
 
-  value_compare value_comp() const { return value_compare(key_comp()); }
+  value_compare value_comp() const {
+    return value_compare(original_key_compare(key_comp()));
+  }
 
   // Verifies the structure of the btree.
   void verify() const;
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/btree_container.h b/chromium/third_party/abseil-cpp/absl/container/internal/btree_container.h
index 03be708e4fd..a99668c7137 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/btree_container.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/btree_container.h
@@ -20,6 +20,7 @@
 #include <iterator>
 #include <utility>
 
+#include "absl/base/attributes.h"
 #include "absl/base/internal/throw_delegate.h"
 #include "absl/container/internal/btree.h"  // IWYU pragma: export
 #include "absl/container/internal/common.h"
@@ -51,7 +52,7 @@ class btree_container {
   using value_type = typename Tree::value_type;
   using size_type = typename Tree::size_type;
   using difference_type = typename Tree::difference_type;
-  using key_compare = typename Tree::key_compare;
+  using key_compare = typename Tree::original_key_compare;
   using value_compare = typename Tree::value_compare;
   using allocator_type = typename Tree::allocator_type;
   using reference = typename Tree::reference;
@@ -176,7 +177,7 @@ class btree_container {
   }
 
   // Utility routines.
-  void clear() { tree_.clear(); }
+  ABSL_ATTRIBUTE_REINITIALIZES void clear() { tree_.clear(); }
   void swap(btree_container &other) { tree_.swap(other.tree_); }
   void verify() const { tree_.verify(); }
 
@@ -214,7 +215,7 @@ class btree_container {
   allocator_type get_allocator() const { return tree_.get_allocator(); }
 
   // The key comparator used by the btree.
-  key_compare key_comp() const { return tree_.key_comp(); }
+  key_compare key_comp() const { return key_compare(tree_.key_comp()); }
   value_compare value_comp() const { return tree_.value_comp(); }
 
   // Support absl::Hash.
@@ -247,7 +248,7 @@ class btree_set_container : public btree_container<Tree> {
   using key_type = typename Tree::key_type;
   using value_type = typename Tree::value_type;
   using size_type = typename Tree::size_type;
-  using key_compare = typename Tree::key_compare;
+  using key_compare = typename Tree::original_key_compare;
   using allocator_type = typename Tree::allocator_type;
   using iterator = typename Tree::iterator;
   using const_iterator = typename Tree::const_iterator;
@@ -398,7 +399,7 @@ class btree_map_container : public btree_set_container<Tree> {
   using key_type = typename Tree::key_type;
   using mapped_type = typename params_type::mapped_type;
   using value_type = typename Tree::value_type;
-  using key_compare = typename Tree::key_compare;
+  using key_compare = typename Tree::original_key_compare;
   using allocator_type = typename Tree::allocator_type;
   using iterator = typename Tree::iterator;
   using const_iterator = typename Tree::const_iterator;
@@ -543,7 +544,7 @@ class btree_multiset_container : public btree_container<Tree> {
   using key_type = typename Tree::key_type;
   using value_type = typename Tree::value_type;
   using size_type = typename Tree::size_type;
-  using key_compare = typename Tree::key_compare;
+  using key_compare = typename Tree::original_key_compare;
   using allocator_type = typename Tree::allocator_type;
   using iterator = typename Tree::iterator;
   using const_iterator = typename Tree::const_iterator;
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/inlined_vector.h b/chromium/third_party/abseil-cpp/absl/container/internal/inlined_vector.h
index b8aec45b79b..49822af0b76 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/inlined_vector.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/inlined_vector.h
@@ -36,6 +36,7 @@ namespace inlined_vector_internal {
 // GCC does not deal very well with the below code
 #if !defined(__clang__) && defined(__GNUC__)
 #pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
 #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
 #endif
 
@@ -955,7 +956,7 @@ auto Storage<T, N, A>::Swap(Storage* other_storage_ptr) -> void {
   swap(*GetAllocPtr(), *other_storage_ptr->GetAllocPtr());
 }
 
-// End ignore "maybe-uninitialized"
+// End ignore "array-bounds" and "maybe-uninitialized"
 #if !defined(__clang__) && defined(__GNUC__)
 #pragma GCC diagnostic pop
 #endif
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_map.h b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_map.h
index 0a02757ddfb..c7df2efc62a 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_map.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_map.h
@@ -51,8 +51,9 @@ class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> {
   using key_arg = typename KeyArgImpl::template type<K, key_type>;
 
   static_assert(!std::is_reference<key_type>::value, "");
-  // TODO(alkis): remove this assertion and verify that reference mapped_type is
-  // supported.
+
+  // TODO(b/187807849): Evaluate whether to support reference mapped_type and
+  // remove this assertion if/when it is supported.
   static_assert(!std::is_reference<mapped_type>::value, "");
 
   using iterator = typename raw_hash_map::raw_hash_set::iterator;
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc
index bfef071f29e..3c72c41a76a 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc
@@ -23,6 +23,12 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace container_internal {
 
+alignas(16) ABSL_CONST_INIT ABSL_DLL const ctrl_t kEmptyGroup[16] = {
+    ctrl_t::kSentinel, ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty};
+
 constexpr size_t Group::kWidth;
 
 // Returns "random" seed.
@@ -37,25 +43,23 @@ inline size_t RandomSeed() {
   return value ^ static_cast<size_t>(reinterpret_cast<uintptr_t>(&counter));
 }
 
-bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl) {
+bool ShouldInsertBackwards(size_t hash, const ctrl_t* ctrl) {
   // To avoid problems with weak hashes and single bit tests, we use % 13.
   // TODO(kfm,sbenza): revisit after we do unconditional mixing
   return (H1(hash, ctrl) ^ RandomSeed()) % 13 > 6;
 }
 
-void ConvertDeletedToEmptyAndFullToDeleted(
-    ctrl_t* ctrl, size_t capacity) {
-  assert(ctrl[capacity] == kSentinel);
+void ConvertDeletedToEmptyAndFullToDeleted(ctrl_t* ctrl, size_t capacity) {
+  assert(ctrl[capacity] == ctrl_t::kSentinel);
   assert(IsValidCapacity(capacity));
-  for (ctrl_t* pos = ctrl; pos != ctrl + capacity + 1; pos += Group::kWidth) {
+  for (ctrl_t* pos = ctrl; pos < ctrl + capacity; pos += Group::kWidth) {
     Group{pos}.ConvertSpecialToEmptyAndFullToDeleted(pos);
   }
   // Copy the cloned ctrl bytes.
-  std::memcpy(ctrl + capacity + 1, ctrl, Group::kWidth);
-  ctrl[capacity] = kSentinel;
+  std::memcpy(ctrl + capacity + 1, ctrl, NumClonedBytes());
+  ctrl[capacity] = ctrl_t::kSentinel;
 }
 
-
 }  // namespace container_internal
 ABSL_NAMESPACE_END
 }  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h
index b23e0078e15..bafafd46ec0 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h
@@ -252,48 +252,53 @@ class BitMask {
   T mask_;
 };
 
-using ctrl_t = signed char;
 using h2_t = uint8_t;
 
 // The values here are selected for maximum performance. See the static asserts
-// below for details.
-enum Ctrl : ctrl_t {
+// below for details. We use an enum class so that when strict aliasing is
+// enabled, the compiler knows ctrl_t doesn't alias other types.
+enum class ctrl_t : int8_t {
   kEmpty = -128,   // 0b10000000
   kDeleted = -2,   // 0b11111110
   kSentinel = -1,  // 0b11111111
 };
 static_assert(
-    kEmpty & kDeleted & kSentinel & 0x80,
+    (static_cast<int8_t>(ctrl_t::kEmpty) &
+     static_cast<int8_t>(ctrl_t::kDeleted) &
+     static_cast<int8_t>(ctrl_t::kSentinel) & 0x80) != 0,
     "Special markers need to have the MSB to make checking for them efficient");
-static_assert(kEmpty < kSentinel && kDeleted < kSentinel,
-              "kEmpty and kDeleted must be smaller than kSentinel to make the "
-              "SIMD test of IsEmptyOrDeleted() efficient");
-static_assert(kSentinel == -1,
-              "kSentinel must be -1 to elide loading it from memory into SIMD "
-              "registers (pcmpeqd xmm, xmm)");
-static_assert(kEmpty == -128,
-              "kEmpty must be -128 to make the SIMD check for its "
+static_assert(
+    ctrl_t::kEmpty < ctrl_t::kSentinel && ctrl_t::kDeleted < ctrl_t::kSentinel,
+    "ctrl_t::kEmpty and ctrl_t::kDeleted must be smaller than "
+    "ctrl_t::kSentinel to make the SIMD test of IsEmptyOrDeleted() efficient");
+static_assert(
+    ctrl_t::kSentinel == static_cast<ctrl_t>(-1),
+    "ctrl_t::kSentinel must be -1 to elide loading it from memory into SIMD "
+    "registers (pcmpeqd xmm, xmm)");
+static_assert(ctrl_t::kEmpty == static_cast<ctrl_t>(-128),
+              "ctrl_t::kEmpty must be -128 to make the SIMD check for its "
               "existence efficient (psignb xmm, xmm)");
-static_assert(~kEmpty & ~kDeleted & kSentinel & 0x7F,
-              "kEmpty and kDeleted must share an unset bit that is not shared "
-              "by kSentinel to make the scalar test for MatchEmptyOrDeleted() "
-              "efficient");
-static_assert(kDeleted == -2,
-              "kDeleted must be -2 to make the implementation of "
+static_assert(
+    (~static_cast<int8_t>(ctrl_t::kEmpty) &
+     ~static_cast<int8_t>(ctrl_t::kDeleted) &
+     static_cast<int8_t>(ctrl_t::kSentinel) & 0x7F) != 0,
+    "ctrl_t::kEmpty and ctrl_t::kDeleted must share an unset bit that is not "
+    "shared by ctrl_t::kSentinel to make the scalar test for "
+    "MatchEmptyOrDeleted() efficient");
+static_assert(ctrl_t::kDeleted == static_cast<ctrl_t>(-2),
+              "ctrl_t::kDeleted must be -2 to make the implementation of "
               "ConvertSpecialToEmptyAndFullToDeleted efficient");
 
 // A single block of empty control bytes for tables without any slots allocated.
 // This enables removing a branch in the hot path of find().
+ABSL_DLL extern const ctrl_t kEmptyGroup[16];
 inline ctrl_t* EmptyGroup() {
-  alignas(16) static constexpr ctrl_t empty_group[] = {
-      kSentinel, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty,
-      kEmpty,    kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty};
-  return const_cast<ctrl_t*>(empty_group);
+  return const_cast<ctrl_t*>(kEmptyGroup);
 }
 
 // Mixes a randomly generated per-process seed with `hash` and `ctrl` to
 // randomize insertion order within groups.
-bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl);
+bool ShouldInsertBackwards(size_t hash, const ctrl_t* ctrl);
 
 // Returns a hash seed.
 //
@@ -309,12 +314,12 @@ inline size_t HashSeed(const ctrl_t* ctrl) {
 inline size_t H1(size_t hash, const ctrl_t* ctrl) {
   return (hash >> 7) ^ HashSeed(ctrl);
 }
-inline ctrl_t H2(size_t hash) { return hash & 0x7F; }
+inline h2_t H2(size_t hash) { return hash & 0x7F; }
 
-inline bool IsEmpty(ctrl_t c) { return c == kEmpty; }
-inline bool IsFull(ctrl_t c) { return c >= 0; }
-inline bool IsDeleted(ctrl_t c) { return c == kDeleted; }
-inline bool IsEmptyOrDeleted(ctrl_t c) { return c < kSentinel; }
+inline bool IsEmpty(ctrl_t c) { return c == ctrl_t::kEmpty; }
+inline bool IsFull(ctrl_t c) { return c >= static_cast<ctrl_t>(0); }
+inline bool IsDeleted(ctrl_t c) { return c == ctrl_t::kDeleted; }
+inline bool IsEmptyOrDeleted(ctrl_t c) { return c < ctrl_t::kSentinel; }
 
 #if ABSL_INTERNAL_RAW_HASH_SET_HAVE_SSE2
 
@@ -351,24 +356,24 @@ struct GroupSse2Impl {
   // Returns a bitmask representing the positions of empty slots.
   BitMask<uint32_t, kWidth> MatchEmpty() const {
 #if ABSL_INTERNAL_RAW_HASH_SET_HAVE_SSSE3
-    // This only works because kEmpty is -128.
+    // This only works because ctrl_t::kEmpty is -128.
     return BitMask<uint32_t, kWidth>(
         _mm_movemask_epi8(_mm_sign_epi8(ctrl, ctrl)));
 #else
-    return Match(static_cast<h2_t>(kEmpty));
+    return Match(static_cast<h2_t>(ctrl_t::kEmpty));
 #endif
   }
 
   // Returns a bitmask representing the positions of empty or deleted slots.
   BitMask<uint32_t, kWidth> MatchEmptyOrDeleted() const {
-    auto special = _mm_set1_epi8(kSentinel);
+    auto special = _mm_set1_epi8(static_cast<int8_t>(ctrl_t::kSentinel));
     return BitMask<uint32_t, kWidth>(
         _mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)));
   }
 
   // Returns the number of trailing empty or deleted elements in the group.
   uint32_t CountLeadingEmptyOrDeleted() const {
-    auto special = _mm_set1_epi8(kSentinel);
+    auto special = _mm_set1_epi8(static_cast<int8_t>(ctrl_t::kSentinel));
     return TrailingZeros(static_cast<uint32_t>(
         _mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)) + 1));
   }
@@ -403,7 +408,7 @@ struct GroupPortableImpl {
     //
     // Caveat: there are false positives but:
     // - they only occur if there is a real match
-    // - they never occur on kEmpty, kDeleted, kSentinel
+    // - they never occur on ctrl_t::kEmpty, ctrl_t::kDeleted, ctrl_t::kSentinel
     // - they will be handled gracefully by subsequent checks in code
     //
     // Example:
@@ -448,6 +453,10 @@ using Group = GroupSse2Impl;
 using Group = GroupPortableImpl;
 #endif
 
+// The number of cloned control bytes that we copy from the beginning to the
+// end of the control bytes array.
+constexpr size_t NumClonedBytes() { return Group::kWidth - 1; }
+
 template <class Policy, class Hash, class Eq, class Alloc>
 class raw_hash_set;
 
@@ -455,8 +464,8 @@ inline bool IsValidCapacity(size_t n) { return ((n + 1) & n) == 0 && n > 0; }
 
 // PRECONDITION:
 //   IsValidCapacity(capacity)
-//   ctrl[capacity] == kSentinel
-//   ctrl[i] != kSentinel for all i < capacity
+//   ctrl[capacity] == ctrl_t::kSentinel
+//   ctrl[i] != ctrl_t::kSentinel for all i < capacity
 // Applies mapping for every byte in ctrl:
 //   DELETED -> EMPTY
 //   EMPTY -> EMPTY
@@ -498,6 +507,22 @@ inline size_t GrowthToLowerboundCapacity(size_t growth) {
   return growth + static_cast<size_t>((static_cast<int64_t>(growth) - 1) / 7);
 }
 
+template <class InputIter>
+size_t SelectBucketCountForIterRange(InputIter first, InputIter last,
+                                     size_t bucket_count) {
+  if (bucket_count != 0) {
+    return bucket_count;
+  }
+  using InputIterCategory =
+      typename std::iterator_traits<InputIter>::iterator_category;
+  if (std::is_base_of<std::random_access_iterator_tag,
+                      InputIterCategory>::value) {
+    return GrowthToLowerboundCapacity(
+        static_cast<size_t>(std::distance(first, last)));
+  }
+  return 0;
+}
+
 inline void AssertIsFull(ctrl_t* ctrl) {
   ABSL_HARDENING_ASSERT((ctrl != nullptr && IsFull(*ctrl)) &&
                         "Invalid operation on iterator. The element might have "
@@ -525,27 +550,28 @@ struct FindInfo {
 //  This is important to make 1 a valid capacity.
 //
 //  - In small mode only the first `capacity()` control bytes after the
-//  sentinel are valid. The rest contain dummy kEmpty values that do not
+//  sentinel are valid. The rest contain dummy ctrl_t::kEmpty values that do not
 //  represent a real slot. This is important to take into account on
 //  find_first_non_full(), where we never try ShouldInsertBackwards() for
 //  small tables.
 inline bool is_small(size_t capacity) { return capacity < Group::kWidth - 1; }
 
-inline probe_seq<Group::kWidth> probe(ctrl_t* ctrl, size_t hash,
+inline probe_seq<Group::kWidth> probe(const ctrl_t* ctrl, size_t hash,
                                       size_t capacity) {
   return probe_seq<Group::kWidth>(H1(hash, ctrl), capacity);
 }
 
 // Probes the raw_hash_set with the probe sequence for hash and returns the
 // pointer to the first empty or deleted slot.
-// NOTE: this function must work with tables having both kEmpty and kDelete
-// in one group. Such tables appears during drop_deletes_without_resize.
+// NOTE: this function must work with tables having both ctrl_t::kEmpty and
+// ctrl_t::kDeleted in one group. Such tables appears during
+// drop_deletes_without_resize.
 //
 // This function is very useful when insertions happen and:
 // - the input is already a set
 // - there are enough slots
 // - the element with the hash is not in the table
-inline FindInfo find_first_non_full(ctrl_t* ctrl, size_t hash,
+inline FindInfo find_first_non_full(const ctrl_t* ctrl, size_t hash,
                                     size_t capacity) {
   auto seq = probe(ctrl, hash, capacity);
   while (true) {
@@ -564,8 +590,39 @@ inline FindInfo find_first_non_full(ctrl_t* ctrl, size_t hash,
       return {seq.offset(mask.LowestBitSet()), seq.index()};
     }
     seq.next();
-    assert(seq.index() < capacity && "full table!");
+    assert(seq.index() <= capacity && "full table!");
+  }
+}
+
+// Reset all ctrl bytes back to ctrl_t::kEmpty, except the sentinel.
+inline void ResetCtrl(size_t capacity, ctrl_t* ctrl, const void* slot,
+                      size_t slot_size) {
+  std::memset(ctrl, static_cast<int8_t>(ctrl_t::kEmpty),
+              capacity + 1 + NumClonedBytes());
+  ctrl[capacity] = ctrl_t::kSentinel;
+  SanitizerPoisonMemoryRegion(slot, slot_size * capacity);
+}
+
+// Sets the control byte, and if `i < NumClonedBytes()`, set the cloned byte
+// at the end too.
+inline void SetCtrl(size_t i, ctrl_t h, size_t capacity, ctrl_t* ctrl,
+                    const void* slot, size_t slot_size) {
+  assert(i < capacity);
+
+  auto* slot_i = static_cast<const char*>(slot) + i * slot_size;
+  if (IsFull(h)) {
+    SanitizerUnpoisonMemoryRegion(slot_i, slot_size);
+  } else {
+    SanitizerPoisonMemoryRegion(slot_i, slot_size);
   }
+
+  ctrl[i] = h;
+  ctrl[((i - NumClonedBytes()) & capacity) + (NumClonedBytes() & capacity)] = h;
+}
+
+inline void SetCtrl(size_t i, h2_t h, size_t capacity, ctrl_t* ctrl,
+                    const void* slot, size_t slot_size) {
+  SetCtrl(i, static_cast<ctrl_t>(h), capacity, ctrl, slot, slot_size);
 }
 
 // Policy: a policy defines how to perform different operations on
@@ -628,7 +685,9 @@ class raw_hash_set {
 
   static Layout MakeLayout(size_t capacity) {
     assert(IsValidCapacity(capacity));
-    return Layout(capacity + Group::kWidth + 1, capacity);
+    // The extra control bytes are for 1 sentinel byte followed by
+    // NumClonedBytes() bytes that are cloned from the beginning.
+    return Layout(capacity + 1 + NumClonedBytes(), capacity);
   }
 
   using AllocTraits = absl::allocator_traits<allocator_type>;
@@ -733,7 +792,7 @@ class raw_hash_set {
         ctrl_ += shift;
         slot_ += shift;
       }
-      if (ABSL_PREDICT_FALSE(*ctrl_ == kSentinel)) ctrl_ = nullptr;
+      if (ABSL_PREDICT_FALSE(*ctrl_ == ctrl_t::kSentinel)) ctrl_ = nullptr;
     }
 
     ctrl_t* ctrl_ = nullptr;
@@ -814,7 +873,8 @@ class raw_hash_set {
   raw_hash_set(InputIter first, InputIter last, size_t bucket_count = 0,
                const hasher& hash = hasher(), const key_equal& eq = key_equal(),
                const allocator_type& alloc = allocator_type())
-      : raw_hash_set(bucket_count, hash, eq, alloc) {
+      : raw_hash_set(SelectBucketCountForIterRange(first, last, bucket_count),
+                     hash, eq, alloc) {
     insert(first, last);
   }
 
@@ -902,7 +962,8 @@ class raw_hash_set {
     for (const auto& v : that) {
       const size_t hash = PolicyTraits::apply(HashElement{hash_ref()}, v);
       auto target = find_first_non_full(ctrl_, hash, capacity_);
-      set_ctrl(target.offset, H2(hash));
+      SetCtrl(target.offset, H2(hash), capacity_, ctrl_, slots_,
+              sizeof(slot_type));
       emplace_at(target.offset, v);
       infoz().RecordInsert(hash, target.probe_length);
     }
@@ -1005,7 +1066,7 @@ class raw_hash_set {
         }
       }
       size_ = 0;
-      reset_ctrl();
+      ResetCtrl(capacity_, ctrl_, slots_, sizeof(slot_type));
       reset_growth_left();
     }
     assert(empty());
@@ -1378,7 +1439,7 @@ class raw_hash_set {
       }
       if (ABSL_PREDICT_TRUE(g.MatchEmpty())) return end();
       seq.next();
-      assert(seq.index() < capacity_ && "full table!");
+      assert(seq.index() <= capacity_ && "full table!");
     }
   }
   template <class K = key_type>
@@ -1526,7 +1587,8 @@ class raw_hash_set {
         static_cast<size_t>(empty_after.TrailingZeros() +
                             empty_before.LeadingZeros()) < Group::kWidth;
 
-    set_ctrl(index, was_never_full ? kEmpty : kDeleted);
+    SetCtrl(index, was_never_full ? ctrl_t::kEmpty : ctrl_t::kDeleted,
+            capacity_, ctrl_, slots_, sizeof(slot_type));
     growth_left() += was_never_full;
     infoz().RecordErase();
   }
@@ -1551,9 +1613,9 @@ class raw_hash_set {
     auto layout = MakeLayout(capacity_);
     char* mem = static_cast<char*>(
         Allocate<Layout::Alignment()>(&alloc_ref(), layout.AllocSize()));
-    ctrl_ = reinterpret_cast<ctrl_t*>(layout.template Pointer<0>(mem));
+    ctrl_ = layout.template Pointer<0>(mem);
     slots_ = layout.template Pointer<1>(mem);
-    reset_ctrl();
+    ResetCtrl(capacity_, ctrl_, slots_, sizeof(slot_type));
     reset_growth_left();
     infoz().RecordStorageChanged(size_, capacity_);
   }
@@ -1592,7 +1654,7 @@ class raw_hash_set {
         auto target = find_first_non_full(ctrl_, hash, capacity_);
         size_t new_i = target.offset;
         total_probe_length += target.probe_length;
-        set_ctrl(new_i, H2(hash));
+        SetCtrl(new_i, H2(hash), capacity_, ctrl_, slots_, sizeof(slot_type));
         PolicyTraits::transfer(&alloc_ref(), slots_ + new_i, old_slots + i);
       }
     }
@@ -1631,35 +1693,35 @@ class raw_hash_set {
     slot_type* slot = reinterpret_cast<slot_type*>(&raw);
     for (size_t i = 0; i != capacity_; ++i) {
       if (!IsDeleted(ctrl_[i])) continue;
-      size_t hash = PolicyTraits::apply(HashElement{hash_ref()},
-                                        PolicyTraits::element(slots_ + i));
-      auto target = find_first_non_full(ctrl_, hash, capacity_);
-      size_t new_i = target.offset;
+      const size_t hash = PolicyTraits::apply(
+          HashElement{hash_ref()}, PolicyTraits::element(slots_ + i));
+      const FindInfo target = find_first_non_full(ctrl_, hash, capacity_);
+      const size_t new_i = target.offset;
       total_probe_length += target.probe_length;
 
       // Verify if the old and new i fall within the same group wrt the hash.
       // If they do, we don't need to move the object as it falls already in the
       // best probe we can.
-      const auto probe_index = [&](size_t pos) {
-        return ((pos - probe(ctrl_, hash, capacity_).offset()) & capacity_) /
-               Group::kWidth;
+      const size_t probe_offset = probe(ctrl_, hash, capacity_).offset();
+      const auto probe_index = [probe_offset, this](size_t pos) {
+        return ((pos - probe_offset) & capacity_) / Group::kWidth;
       };
 
       // Element doesn't move.
       if (ABSL_PREDICT_TRUE(probe_index(new_i) == probe_index(i))) {
-        set_ctrl(i, H2(hash));
+        SetCtrl(i, H2(hash), capacity_, ctrl_, slots_, sizeof(slot_type));
         continue;
       }
       if (IsEmpty(ctrl_[new_i])) {
         // Transfer element to the empty spot.
-        // set_ctrl poisons/unpoisons the slots so we have to call it at the
+        // SetCtrl poisons/unpoisons the slots so we have to call it at the
         // right time.
-        set_ctrl(new_i, H2(hash));
+        SetCtrl(new_i, H2(hash), capacity_, ctrl_, slots_, sizeof(slot_type));
         PolicyTraits::transfer(&alloc_ref(), slots_ + new_i, slots_ + i);
-        set_ctrl(i, kEmpty);
+        SetCtrl(i, ctrl_t::kEmpty, capacity_, ctrl_, slots_, sizeof(slot_type));
       } else {
         assert(IsDeleted(ctrl_[new_i]));
-        set_ctrl(new_i, H2(hash));
+        SetCtrl(new_i, H2(hash), capacity_, ctrl_, slots_, sizeof(slot_type));
         // Until we are done rehashing, DELETED marks previously FULL slots.
         // Swap i and new_i elements.
         PolicyTraits::transfer(&alloc_ref(), slot, slots_ + i);
@@ -1675,8 +1737,50 @@ class raw_hash_set {
   void rehash_and_grow_if_necessary() {
     if (capacity_ == 0) {
       resize(1);
-    } else if (size() <= CapacityToGrowth(capacity()) / 2) {
+    } else if (capacity_ > Group::kWidth &&
+               // Do these calcuations in 64-bit to avoid overflow.
+               size() * uint64_t{32} <= capacity_ * uint64_t{25}) {
       // Squash DELETED without growing if there is enough capacity.
+      //
+      // Rehash in place if the current size is <= 25/32 of capacity_.
+      // Rationale for such a high factor: 1) drop_deletes_without_resize() is
+      // faster than resize, and 2) it takes quite a bit of work to add
+      // tombstones.  In the worst case, seems to take approximately 4
+      // insert/erase pairs to create a single tombstone and so if we are
+      // rehashing because of tombstones, we can afford to rehash-in-place as
+      // long as we are reclaiming at least 1/8 the capacity without doing more
+      // than 2X the work.  (Where "work" is defined to be size() for rehashing
+      // or rehashing in place, and 1 for an insert or erase.)  But rehashing in
+      // place is faster per operation than inserting or even doubling the size
+      // of the table, so we actually afford to reclaim even less space from a
+      // resize-in-place.  The decision is to rehash in place if we can reclaim
+      // at about 1/8th of the usable capacity (specifically 3/28 of the
+      // capacity) which means that the total cost of rehashing will be a small
+      // fraction of the total work.
+      //
+      // Here is output of an experiment using the BM_CacheInSteadyState
+      // benchmark running the old case (where we rehash-in-place only if we can
+      // reclaim at least 7/16*capacity_) vs. this code (which rehashes in place
+      // if we can recover 3/32*capacity_).
+      //
+      // Note that although in the worst-case number of rehashes jumped up from
+      // 15 to 190, but the number of operations per second is almost the same.
+      //
+      // Abridged output of running BM_CacheInSteadyState benchmark from
+      // raw_hash_set_benchmark.   N is the number of insert/erase operations.
+      //
+      //      | OLD (recover >= 7/16        | NEW (recover >= 3/32)
+      // size |    N/s LoadFactor NRehashes |    N/s LoadFactor NRehashes
+      //  448 | 145284       0.44        18 | 140118       0.44        19
+      //  493 | 152546       0.24        11 | 151417       0.48        28
+      //  538 | 151439       0.26        11 | 151152       0.53        38
+      //  583 | 151765       0.28        11 | 150572       0.57        50
+      //  628 | 150241       0.31        11 | 150853       0.61        66
+      //  672 | 149602       0.33        12 | 150110       0.66        90
+      //  717 | 149998       0.35        12 | 149531       0.70       129
+      //  762 | 149836       0.37        13 | 148559       0.74       190
+      //  807 | 149736       0.39        14 | 151107       0.39        14
+      //  852 | 150204       0.42        15 | 151019       0.42        15
       drop_deletes_without_resize();
     } else {
       // Otherwise grow the container.
@@ -1696,7 +1800,7 @@ class raw_hash_set {
       }
       if (ABSL_PREDICT_TRUE(g.MatchEmpty())) return false;
       seq.next();
-      assert(seq.index() < capacity_ && "full table!");
+      assert(seq.index() <= capacity_ && "full table!");
     }
     return false;
   }
@@ -1728,7 +1832,7 @@ class raw_hash_set {
       }
       if (ABSL_PREDICT_TRUE(g.MatchEmpty())) break;
       seq.next();
-      assert(seq.index() < capacity_ && "full table!");
+      assert(seq.index() <= capacity_ && "full table!");
     }
     return {prepare_insert(hash), true};
   }
@@ -1742,7 +1846,8 @@ class raw_hash_set {
     }
     ++size_;
     growth_left() -= IsEmpty(ctrl_[target.offset]);
-    set_ctrl(target.offset, H2(hash));
+    SetCtrl(target.offset, H2(hash), capacity_, ctrl_, slots_,
+            sizeof(slot_type));
     infoz().RecordInsert(hash, target.probe_length);
     return target.offset;
   }
@@ -1771,33 +1876,10 @@ class raw_hash_set {
  private:
   friend struct RawHashSetTestOnlyAccess;
 
-  // Reset all ctrl bytes back to kEmpty, except the sentinel.
-  void reset_ctrl() {
-    std::memset(ctrl_, kEmpty, capacity_ + Group::kWidth);
-    ctrl_[capacity_] = kSentinel;
-    SanitizerPoisonMemoryRegion(slots_, sizeof(slot_type) * capacity_);
-  }
-
   void reset_growth_left() {
     growth_left() = CapacityToGrowth(capacity()) - size_;
   }
 
-  // Sets the control byte, and if `i < Group::kWidth`, set the cloned byte at
-  // the end too.
-  void set_ctrl(size_t i, ctrl_t h) {
-    assert(i < capacity_);
-
-    if (IsFull(h)) {
-      SanitizerUnpoisonObject(slots_ + i);
-    } else {
-      SanitizerPoisonObject(slots_ + i);
-    }
-
-    ctrl_[i] = h;
-    ctrl_[((i - Group::kWidth) & capacity_) + 1 +
-          ((Group::kWidth - 1) & capacity_)] = h;
-  }
-
   size_t& growth_left() { return settings_.template get<0>(); }
 
   HashtablezInfoHandle& infoz() { return settings_.template get<1>(); }
@@ -1814,10 +1896,10 @@ class raw_hash_set {
   // TODO(alkis): Investigate removing some of these fields:
   // - ctrl/slots can be derived from each other
   // - size can be moved into the slot array
-  ctrl_t* ctrl_ = EmptyGroup();    // [(capacity + 1) * ctrl_t]
-  slot_type* slots_ = nullptr;     // [capacity * slot_type]
-  size_t size_ = 0;                // number of full slots
-  size_t capacity_ = 0;            // total number of slots
+  ctrl_t* ctrl_ = EmptyGroup();  // [(capacity + 1 + NumClonedBytes()) * ctrl_t]
+  slot_type* slots_ = nullptr;   // [capacity * slot_type]
+  size_t size_ = 0;              // number of full slots
+  size_t capacity_ = 0;          // total number of slots
   absl::container_internal::CompressedTuple<size_t /* growth_left */,
                                             HashtablezInfoHandle, hasher,
                                             key_equal, allocator_type>
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_benchmark.cc b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_benchmark.cc
index f9be2c5ac7c..c886d3ad43c 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_benchmark.cc
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_benchmark.cc
@@ -254,6 +254,23 @@ void BM_CopyAssign(benchmark::State& state) {
 }
 BENCHMARK(BM_CopyAssign)->Range(128, 4096);
 
+void BM_RangeCtor(benchmark::State& state) {
+  std::random_device rd;
+  std::mt19937 rng(rd());
+  std::uniform_int_distribution<uint64_t> dist(0, ~uint64_t{});
+  std::vector<int> values;
+  const size_t desired_size = state.range(0);
+  while (values.size() < desired_size) {
+    values.emplace_back(dist(rng));
+  }
+
+  for (auto unused : state) {
+    IntTable t{values.begin(), values.end()};
+    benchmark::DoNotOptimize(t);
+  }
+}
+BENCHMARK(BM_RangeCtor)->Range(128, 65536);
+
 void BM_NoOpReserveIntTable(benchmark::State& state) {
   IntTable t;
   t.reserve(100000);
@@ -298,9 +315,17 @@ void BM_ReserveStringTable(benchmark::State& state) {
 }
 BENCHMARK(BM_ReserveStringTable)->Range(128, 4096);
 
+// Like std::iota, except that ctrl_t doesn't support operator++.
+template <typename CtrlIter>
+void Iota(CtrlIter begin, CtrlIter end, int value) {
+  for (; begin != end; ++begin, ++value) {
+    *begin = static_cast<ctrl_t>(value);
+  }
+}
+
 void BM_Group_Match(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
-  std::iota(group.begin(), group.end(), -4);
+  Iota(group.begin(), group.end(), -4);
   Group g{group.data()};
   h2_t h = 1;
   for (auto _ : state) {
@@ -312,7 +337,7 @@ BENCHMARK(BM_Group_Match);
 
 void BM_Group_MatchEmpty(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
-  std::iota(group.begin(), group.end(), -4);
+  Iota(group.begin(), group.end(), -4);
   Group g{group.data()};
   for (auto _ : state) ::benchmark::DoNotOptimize(g.MatchEmpty());
 }
@@ -320,7 +345,7 @@ BENCHMARK(BM_Group_MatchEmpty);
 
 void BM_Group_MatchEmptyOrDeleted(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
-  std::iota(group.begin(), group.end(), -4);
+  Iota(group.begin(), group.end(), -4);
   Group g{group.data()};
   for (auto _ : state) ::benchmark::DoNotOptimize(g.MatchEmptyOrDeleted());
 }
@@ -328,7 +353,7 @@ BENCHMARK(BM_Group_MatchEmptyOrDeleted);
 
 void BM_Group_CountLeadingEmptyOrDeleted(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
-  std::iota(group.begin(), group.end(), -2);
+  Iota(group.begin(), group.end(), -2);
   Group g{group.data()};
   for (auto _ : state)
     ::benchmark::DoNotOptimize(g.CountLeadingEmptyOrDeleted());
@@ -337,7 +362,7 @@ BENCHMARK(BM_Group_CountLeadingEmptyOrDeleted);
 
 void BM_Group_MatchFirstEmptyOrDeleted(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
-  std::iota(group.begin(), group.end(), -2);
+  Iota(group.begin(), group.end(), -2);
   Group g{group.data()};
   for (auto _ : state) ::benchmark::DoNotOptimize(*g.MatchEmptyOrDeleted());
 }
@@ -346,8 +371,11 @@ BENCHMARK(BM_Group_MatchFirstEmptyOrDeleted);
 void BM_DropDeletes(benchmark::State& state) {
   constexpr size_t capacity = (1 << 20) - 1;
   std::vector<ctrl_t> ctrl(capacity + 1 + Group::kWidth);
-  ctrl[capacity] = kSentinel;
-  std::vector<ctrl_t> pattern = {kEmpty, 2, kDeleted, 2, kEmpty, 1, kDeleted};
+  ctrl[capacity] = ctrl_t::kSentinel;
+  std::vector<ctrl_t> pattern = {ctrl_t::kEmpty,   static_cast<ctrl_t>(2),
+                                 ctrl_t::kDeleted, static_cast<ctrl_t>(2),
+                                 ctrl_t::kEmpty,   static_cast<ctrl_t>(1),
+                                 ctrl_t::kDeleted};
   for (size_t i = 0; i != capacity; ++i) {
     ctrl[i] = pattern[i % pattern.size()];
   }
@@ -378,6 +406,12 @@ bool CodegenAbslRawHashSetInt64FindNeEnd(
   return table->find(key) != table->end();
 }
 
+auto CodegenAbslRawHashSetInt64Insert(absl::container_internal::IntTable* table,
+                                      int64_t key)
+    -> decltype(table->insert(key)) {
+  return table->insert(key);
+}
+
 bool CodegenAbslRawHashSetInt64Contains(
     absl::container_internal::IntTable* table, int64_t key) {
   return table->contains(key);
@@ -391,6 +425,7 @@ void CodegenAbslRawHashSetInt64Iterate(
 int odr =
     (::benchmark::DoNotOptimize(std::make_tuple(
          &CodegenAbslRawHashSetInt64Find, &CodegenAbslRawHashSetInt64FindNeEnd,
+         &CodegenAbslRawHashSetInt64Insert,
          &CodegenAbslRawHashSetInt64Contains,
          &CodegenAbslRawHashSetInt64Iterate)),
      1);
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_test.cc b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_test.cc
index 7dac65a03be..4fb31fad678 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/raw_hash_set_test.cc
@@ -58,6 +58,9 @@ using ::testing::Lt;
 using ::testing::Pair;
 using ::testing::UnorderedElementsAre;
 
+// Convenience function to static cast to ctrl_t.
+ctrl_t CtrlT(int i) { return static_cast<ctrl_t>(i); }
+
 TEST(Util, NormalizeCapacity) {
   EXPECT_EQ(1, NormalizeCapacity(0));
   EXPECT_EQ(1, NormalizeCapacity(1));
@@ -170,15 +173,19 @@ TEST(Group, EmptyGroup) {
 
 TEST(Group, Match) {
   if (Group::kWidth == 16) {
-    ctrl_t group[] = {kEmpty, 1, kDeleted, 3, kEmpty, 5, kSentinel, 7,
-                      7,      5, 3,        1, 1,      1, 1,         1};
+    ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted,  CtrlT(3),
+                      ctrl_t::kEmpty, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
+                      CtrlT(7),       CtrlT(5), CtrlT(3),          CtrlT(1),
+                      CtrlT(1),       CtrlT(1), CtrlT(1),          CtrlT(1)};
     EXPECT_THAT(Group{group}.Match(0), ElementsAre());
     EXPECT_THAT(Group{group}.Match(1), ElementsAre(1, 11, 12, 13, 14, 15));
     EXPECT_THAT(Group{group}.Match(3), ElementsAre(3, 10));
     EXPECT_THAT(Group{group}.Match(5), ElementsAre(5, 9));
     EXPECT_THAT(Group{group}.Match(7), ElementsAre(7, 8));
   } else if (Group::kWidth == 8) {
-    ctrl_t group[] = {kEmpty, 1, 2, kDeleted, 2, 1, kSentinel, 1};
+    ctrl_t group[] = {ctrl_t::kEmpty,    CtrlT(1), CtrlT(2),
+                      ctrl_t::kDeleted,  CtrlT(2), CtrlT(1),
+                      ctrl_t::kSentinel, CtrlT(1)};
     EXPECT_THAT(Group{group}.Match(0), ElementsAre());
     EXPECT_THAT(Group{group}.Match(1), ElementsAre(1, 5, 7));
     EXPECT_THAT(Group{group}.Match(2), ElementsAre(2, 4));
@@ -189,11 +196,15 @@ TEST(Group, Match) {
 
 TEST(Group, MatchEmpty) {
   if (Group::kWidth == 16) {
-    ctrl_t group[] = {kEmpty, 1, kDeleted, 3, kEmpty, 5, kSentinel, 7,
-                      7,      5, 3,        1, 1,      1, 1,         1};
+    ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted,  CtrlT(3),
+                      ctrl_t::kEmpty, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
+                      CtrlT(7),       CtrlT(5), CtrlT(3),          CtrlT(1),
+                      CtrlT(1),       CtrlT(1), CtrlT(1),          CtrlT(1)};
     EXPECT_THAT(Group{group}.MatchEmpty(), ElementsAre(0, 4));
   } else if (Group::kWidth == 8) {
-    ctrl_t group[] = {kEmpty, 1, 2, kDeleted, 2, 1, kSentinel, 1};
+    ctrl_t group[] = {ctrl_t::kEmpty,    CtrlT(1), CtrlT(2),
+                      ctrl_t::kDeleted,  CtrlT(2), CtrlT(1),
+                      ctrl_t::kSentinel, CtrlT(1)};
     EXPECT_THAT(Group{group}.MatchEmpty(), ElementsAre(0));
   } else {
     FAIL() << "No test coverage for Group::kWidth==" << Group::kWidth;
@@ -202,11 +213,15 @@ TEST(Group, MatchEmpty) {
 
 TEST(Group, MatchEmptyOrDeleted) {
   if (Group::kWidth == 16) {
-    ctrl_t group[] = {kEmpty, 1, kDeleted, 3, kEmpty, 5, kSentinel, 7,
-                      7,      5, 3,        1, 1,      1, 1,         1};
+    ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted,  CtrlT(3),
+                      ctrl_t::kEmpty, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
+                      CtrlT(7),       CtrlT(5), CtrlT(3),          CtrlT(1),
+                      CtrlT(1),       CtrlT(1), CtrlT(1),          CtrlT(1)};
     EXPECT_THAT(Group{group}.MatchEmptyOrDeleted(), ElementsAre(0, 2, 4));
   } else if (Group::kWidth == 8) {
-    ctrl_t group[] = {kEmpty, 1, 2, kDeleted, 2, 1, kSentinel, 1};
+    ctrl_t group[] = {ctrl_t::kEmpty,    CtrlT(1), CtrlT(2),
+                      ctrl_t::kDeleted,  CtrlT(2), CtrlT(1),
+                      ctrl_t::kSentinel, CtrlT(1)};
     EXPECT_THAT(Group{group}.MatchEmptyOrDeleted(), ElementsAre(0, 3));
   } else {
     FAIL() << "No test coverage for Group::kWidth==" << Group::kWidth;
@@ -217,28 +232,32 @@ TEST(Batch, DropDeletes) {
   constexpr size_t kCapacity = 63;
   constexpr size_t kGroupWidth = container_internal::Group::kWidth;
   std::vector<ctrl_t> ctrl(kCapacity + 1 + kGroupWidth);
-  ctrl[kCapacity] = kSentinel;
-  std::vector<ctrl_t> pattern = {kEmpty, 2, kDeleted, 2, kEmpty, 1, kDeleted};
+  ctrl[kCapacity] = ctrl_t::kSentinel;
+  std::vector<ctrl_t> pattern = {
+      ctrl_t::kEmpty, CtrlT(2), ctrl_t::kDeleted, CtrlT(2),
+      ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted};
   for (size_t i = 0; i != kCapacity; ++i) {
     ctrl[i] = pattern[i % pattern.size()];
     if (i < kGroupWidth - 1)
       ctrl[i + kCapacity + 1] = pattern[i % pattern.size()];
   }
   ConvertDeletedToEmptyAndFullToDeleted(ctrl.data(), kCapacity);
-  ASSERT_EQ(ctrl[kCapacity], kSentinel);
-  for (size_t i = 0; i < kCapacity + 1 + kGroupWidth; ++i) {
+  ASSERT_EQ(ctrl[kCapacity], ctrl_t::kSentinel);
+  for (size_t i = 0; i < kCapacity + kGroupWidth; ++i) {
     ctrl_t expected = pattern[i % (kCapacity + 1) % pattern.size()];
-    if (i == kCapacity) expected = kSentinel;
-    if (expected == kDeleted) expected = kEmpty;
-    if (IsFull(expected)) expected = kDeleted;
+    if (i == kCapacity) expected = ctrl_t::kSentinel;
+    if (expected == ctrl_t::kDeleted) expected = ctrl_t::kEmpty;
+    if (IsFull(expected)) expected = ctrl_t::kDeleted;
     EXPECT_EQ(ctrl[i], expected)
-        << i << " " << int{pattern[i % pattern.size()]};
+        << i << " " << static_cast<int>(pattern[i % pattern.size()]);
   }
 }
 
 TEST(Group, CountLeadingEmptyOrDeleted) {
-  const std::vector<ctrl_t> empty_examples = {kEmpty, kDeleted};
-  const std::vector<ctrl_t> full_examples = {0, 1, 2, 3, 5, 9, 127, kSentinel};
+  const std::vector<ctrl_t> empty_examples = {ctrl_t::kEmpty, ctrl_t::kDeleted};
+  const std::vector<ctrl_t> full_examples = {
+      CtrlT(0), CtrlT(1), CtrlT(2),   CtrlT(3),
+      CtrlT(5), CtrlT(9), CtrlT(127), ctrl_t::kSentinel};
 
   for (ctrl_t empty : empty_examples) {
     std::vector<ctrl_t> e(Group::kWidth, empty);
@@ -294,6 +313,7 @@ struct ValuePolicy {
 };
 
 using IntPolicy = ValuePolicy<int64_t>;
+using Uint8Policy = ValuePolicy<uint8_t>;
 
 class StringPolicy {
   template <class F, class K, class V,
@@ -374,6 +394,13 @@ struct IntTable
   using Base::Base;
 };
 
+struct Uint8Table
+    : raw_hash_set<Uint8Policy, container_internal::hash_default_hash<uint8_t>,
+                   std::equal_to<uint8_t>, std::allocator<uint8_t>> {
+  using Base = typename Uint8Table::raw_hash_set;
+  using Base::Base;
+};
+
 template <typename T>
 struct CustomAlloc : std::allocator<T> {
   CustomAlloc() {}
@@ -541,6 +568,37 @@ TEST(Table, InsertCollisionAndFindAfterDelete) {
   EXPECT_TRUE(t.empty());
 }
 
+TEST(Table, InsertWithinCapacity) {
+  IntTable t;
+  t.reserve(10);
+  const size_t original_capacity = t.capacity();
+  const auto addr = [&](int i) {
+    return reinterpret_cast<uintptr_t>(&*t.find(i));
+  };
+  // Inserting an element does not change capacity.
+  t.insert(0);
+  EXPECT_THAT(t.capacity(), original_capacity);
+  const uintptr_t original_addr_0 = addr(0);
+  // Inserting another element does not rehash.
+  t.insert(1);
+  EXPECT_THAT(t.capacity(), original_capacity);
+  EXPECT_THAT(addr(0), original_addr_0);
+  // Inserting lots of duplicate elements does not rehash.
+  for (int i = 0; i < 100; ++i) {
+    t.insert(i % 10);
+  }
+  EXPECT_THAT(t.capacity(), original_capacity);
+  EXPECT_THAT(addr(0), original_addr_0);
+  // Inserting a range of duplicate elements does not rehash.
+  std::vector<int> dup_range;
+  for (int i = 0; i < 100; ++i) {
+    dup_range.push_back(i % 10);
+  }
+  t.insert(dup_range.begin(), dup_range.end());
+  EXPECT_THAT(t.capacity(), original_capacity);
+  EXPECT_THAT(addr(0), original_addr_0);
+}
+
 TEST(Table, LazyEmplace) {
   StringTable t;
   bool called = false;
@@ -588,28 +646,53 @@ TEST(Table, Contains2) {
 }
 
 int decompose_constructed;
+int decompose_copy_constructed;
+int decompose_copy_assigned;
+int decompose_move_constructed;
+int decompose_move_assigned;
 struct DecomposeType {
-  DecomposeType(int i) : i(i) {  // NOLINT
+  DecomposeType(int i = 0) : i(i) {  // NOLINT
     ++decompose_constructed;
   }
 
   explicit DecomposeType(const char* d) : DecomposeType(*d) {}
 
+  DecomposeType(const DecomposeType& other) : i(other.i) {
+    ++decompose_copy_constructed;
+  }
+  DecomposeType& operator=(const DecomposeType& other) {
+    ++decompose_copy_assigned;
+    i = other.i;
+    return *this;
+  }
+  DecomposeType(DecomposeType&& other) : i(other.i) {
+    ++decompose_move_constructed;
+  }
+  DecomposeType& operator=(DecomposeType&& other) {
+    ++decompose_move_assigned;
+    i = other.i;
+    return *this;
+  }
+
   int i;
 };
 
 struct DecomposeHash {
   using is_transparent = void;
-  size_t operator()(DecomposeType a) const { return a.i; }
+  size_t operator()(const DecomposeType& a) const { return a.i; }
   size_t operator()(int a) const { return a; }
   size_t operator()(const char* a) const { return *a; }
 };
 
 struct DecomposeEq {
   using is_transparent = void;
-  bool operator()(DecomposeType a, DecomposeType b) const { return a.i == b.i; }
-  bool operator()(DecomposeType a, int b) const { return a.i == b; }
-  bool operator()(DecomposeType a, const char* b) const { return a.i == *b; }
+  bool operator()(const DecomposeType& a, const DecomposeType& b) const {
+    return a.i == b.i;
+  }
+  bool operator()(const DecomposeType& a, int b) const { return a.i == b; }
+  bool operator()(const DecomposeType& a, const char* b) const {
+    return a.i == *b;
+  }
 };
 
 struct DecomposePolicy {
@@ -619,9 +702,9 @@ struct DecomposePolicy {
 
   template <typename T>
   static void construct(void*, DecomposeType* slot, T&& v) {
-    *slot = DecomposeType(std::forward<T>(v));
+    ::new (slot) DecomposeType(std::forward<T>(v));
   }
-  static void destroy(void*, DecomposeType*) {}
+  static void destroy(void*, DecomposeType* slot) { slot->~DecomposeType(); }
   static DecomposeType& element(slot_type* slot) { return *slot; }
 
   template <class F, class T>
@@ -636,8 +719,13 @@ void TestDecompose(bool construct_three) {
   const int one = 1;
   const char* three_p = "3";
   const auto& three = three_p;
+  const int elem_vector_count = 256;
+  std::vector<DecomposeType> elem_vector(elem_vector_count, DecomposeType{0});
+  std::iota(elem_vector.begin(), elem_vector.end(), 0);
 
-  raw_hash_set<DecomposePolicy, Hash, Eq, std::allocator<int>> set1;
+  using DecomposeSet =
+      raw_hash_set<DecomposePolicy, Hash, Eq, std::allocator<int>>;
+  DecomposeSet set1;
 
   decompose_constructed = 0;
   int expected_constructed = 0;
@@ -695,20 +783,72 @@ void TestDecompose(bool construct_three) {
     expected_constructed += construct_three;
     EXPECT_EQ(expected_constructed, decompose_constructed);
   }
+
+  decompose_copy_constructed = 0;
+  decompose_copy_assigned = 0;
+  decompose_move_constructed = 0;
+  decompose_move_assigned = 0;
+  int expected_copy_constructed = 0;
+  int expected_move_constructed = 0;
+  {  // raw_hash_set(first, last) with random-access iterators
+    DecomposeSet set2(elem_vector.begin(), elem_vector.end());
+    // Expect exactly one copy-constructor call for each element if no
+    // rehashing is done.
+    expected_copy_constructed += elem_vector_count;
+    EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
+    EXPECT_EQ(expected_move_constructed, decompose_move_constructed);
+    EXPECT_EQ(0, decompose_move_assigned);
+    EXPECT_EQ(0, decompose_copy_assigned);
+  }
+
+  {  // raw_hash_set(first, last) with forward iterators
+    std::list<DecomposeType> elem_list(elem_vector.begin(), elem_vector.end());
+    expected_copy_constructed = decompose_copy_constructed;
+    DecomposeSet set2(elem_list.begin(), elem_list.end());
+    // Expect exactly N elements copied into set, expect at most 2*N elements
+    // moving internally for all resizing needed (for a growth factor of 2).
+    expected_copy_constructed += elem_vector_count;
+    EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
+    expected_move_constructed += elem_vector_count;
+    EXPECT_LT(expected_move_constructed, decompose_move_constructed);
+    expected_move_constructed += elem_vector_count;
+    EXPECT_GE(expected_move_constructed, decompose_move_constructed);
+    EXPECT_EQ(0, decompose_move_assigned);
+    EXPECT_EQ(0, decompose_copy_assigned);
+    expected_copy_constructed = decompose_copy_constructed;
+    expected_move_constructed = decompose_move_constructed;
+  }
+
+  {  // insert(first, last)
+    DecomposeSet set2;
+    set2.insert(elem_vector.begin(), elem_vector.end());
+    // Expect exactly N elements copied into set, expect at most 2*N elements
+    // moving internally for all resizing needed (for a growth factor of 2).
+    const int expected_new_elements = elem_vector_count;
+    const int expected_max_element_moves = 2 * elem_vector_count;
+    expected_copy_constructed += expected_new_elements;
+    EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
+    expected_move_constructed += expected_max_element_moves;
+    EXPECT_GE(expected_move_constructed, decompose_move_constructed);
+    EXPECT_EQ(0, decompose_move_assigned);
+    EXPECT_EQ(0, decompose_copy_assigned);
+    expected_copy_constructed = decompose_copy_constructed;
+    expected_move_constructed = decompose_move_constructed;
+  }
 }
 
 TEST(Table, Decompose) {
   TestDecompose<DecomposeHash, DecomposeEq>(false);
 
   struct TransparentHashIntOverload {
-    size_t operator()(DecomposeType a) const { return a.i; }
+    size_t operator()(const DecomposeType& a) const { return a.i; }
     size_t operator()(int a) const { return a; }
   };
   struct TransparentEqIntOverload {
-    bool operator()(DecomposeType a, DecomposeType b) const {
+    bool operator()(const DecomposeType& a, const DecomposeType& b) const {
       return a.i == b.i;
     }
-    bool operator()(DecomposeType a, int b) const { return a.i == b; }
+    bool operator()(const DecomposeType& a, int b) const { return a.i == b; }
   };
   TestDecompose<TransparentHashIntOverload, DecomposeEq>(true);
   TestDecompose<TransparentHashIntOverload, TransparentEqIntOverload>(true);
@@ -750,7 +890,7 @@ TEST(Table, RehashWithNoResize) {
   const size_t capacity = t.capacity();
 
   // Remove elements from all groups except the first and the last one.
-  // All elements removed from full groups will be marked as kDeleted.
+  // All elements removed from full groups will be marked as ctrl_t::kDeleted.
   const size_t erase_begin = Group::kWidth / 2;
   const size_t erase_end = (t.size() / Group::kWidth - 1) * Group::kWidth;
   for (size_t i = erase_begin; i < erase_end; ++i) {
@@ -1978,6 +2118,36 @@ TEST(Sanitizer, PoisoningOnErase) {
 }
 #endif  // ABSL_HAVE_ADDRESS_SANITIZER
 
+TEST(Table, AlignOne) {
+  // We previously had a bug in which we were copying a control byte over the
+  // first slot when alignof(value_type) is 1. We test repeated
+  // insertions/erases and verify that the behavior is correct.
+  Uint8Table t;
+  std::unordered_set<uint8_t> verifier;  // NOLINT
+
+  // Do repeated insertions/erases from the table.
+  for (int64_t i = 0; i < 100000; ++i) {
+    SCOPED_TRACE(i);
+    const uint8_t u = (i * -i) & 0xFF;
+    auto it = t.find(u);
+    auto verifier_it = verifier.find(u);
+    if (it == t.end()) {
+      ASSERT_EQ(verifier_it, verifier.end());
+      t.insert(u);
+      verifier.insert(u);
+    } else {
+      ASSERT_NE(verifier_it, verifier.end());
+      t.erase(it);
+      verifier.erase(verifier_it);
+    }
+  }
+
+  EXPECT_EQ(t.size(), verifier.size());
+  for (uint8_t u : t) {
+    EXPECT_EQ(verifier.count(u), 1);
+  }
+}
+
 }  // namespace
 }  // namespace container_internal
 ABSL_NAMESPACE_END
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/unordered_map_modifiers_test.h b/chromium/third_party/abseil-cpp/absl/container/internal/unordered_map_modifiers_test.h
index 8c9ca779a42..d3543936f79 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/unordered_map_modifiers_test.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/unordered_map_modifiers_test.h
@@ -81,6 +81,38 @@ TYPED_TEST_P(ModifiersTest, InsertRange) {
   ASSERT_THAT(items(m), ::testing::UnorderedElementsAreArray(values));
 }
 
+TYPED_TEST_P(ModifiersTest, InsertWithinCapacity) {
+  using T = hash_internal::GeneratedType<TypeParam>;
+  using V = typename TypeParam::mapped_type;
+  T val = hash_internal::Generator<T>()();
+  TypeParam m;
+  m.reserve(10);
+  const size_t original_capacity = m.bucket_count();
+  m.insert(val);
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+  T val2 = {val.first, hash_internal::Generator<V>()()};
+  m.insert(val2);
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+}
+
+TYPED_TEST_P(ModifiersTest, InsertRangeWithinCapacity) {
+#if !defined(__GLIBCXX__)
+  using T = hash_internal::GeneratedType<TypeParam>;
+  std::vector<T> base_values;
+  std::generate_n(std::back_inserter(base_values), 10,
+                  hash_internal::Generator<T>());
+  std::vector<T> values;
+  while (values.size() != 100) {
+    std::copy_n(base_values.begin(), 10, std::back_inserter(values));
+  }
+  TypeParam m;
+  m.reserve(10);
+  const size_t original_capacity = m.bucket_count();
+  m.insert(values.begin(), values.end());
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+#endif
+}
+
 TYPED_TEST_P(ModifiersTest, InsertOrAssign) {
 #ifdef UNORDERED_MAP_CXX17
   using std::get;
@@ -266,9 +298,10 @@ TYPED_TEST_P(ModifiersTest, Swap) {
 // TODO(alkis): Write tests for merge.
 
 REGISTER_TYPED_TEST_CASE_P(ModifiersTest, Clear, Insert, InsertHint,
-                           InsertRange, InsertOrAssign, InsertOrAssignHint,
-                           Emplace, EmplaceHint, TryEmplace, TryEmplaceHint,
-                           Erase, EraseRange, EraseKey, Swap);
+                           InsertRange, InsertWithinCapacity,
+                           InsertRangeWithinCapacity, InsertOrAssign,
+                           InsertOrAssignHint, Emplace, EmplaceHint, TryEmplace,
+                           TryEmplaceHint, Erase, EraseRange, EraseKey, Swap);
 
 template <typename Type>
 struct is_unique_ptr : std::false_type {};
diff --git a/chromium/third_party/abseil-cpp/absl/container/internal/unordered_set_modifiers_test.h b/chromium/third_party/abseil-cpp/absl/container/internal/unordered_set_modifiers_test.h
index 26be58d99f2..6e473e45da9 100644
--- a/chromium/third_party/abseil-cpp/absl/container/internal/unordered_set_modifiers_test.h
+++ b/chromium/third_party/abseil-cpp/absl/container/internal/unordered_set_modifiers_test.h
@@ -74,6 +74,36 @@ TYPED_TEST_P(ModifiersTest, InsertRange) {
   ASSERT_THAT(keys(m), ::testing::UnorderedElementsAreArray(values));
 }
 
+TYPED_TEST_P(ModifiersTest, InsertWithinCapacity) {
+  using T = hash_internal::GeneratedType<TypeParam>;
+  T val = hash_internal::Generator<T>()();
+  TypeParam m;
+  m.reserve(10);
+  const size_t original_capacity = m.bucket_count();
+  m.insert(val);
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+  m.insert(val);
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+}
+
+TYPED_TEST_P(ModifiersTest, InsertRangeWithinCapacity) {
+#if !defined(__GLIBCXX__)
+  using T = hash_internal::GeneratedType<TypeParam>;
+  std::vector<T> base_values;
+  std::generate_n(std::back_inserter(base_values), 10,
+                  hash_internal::Generator<T>());
+  std::vector<T> values;
+  while (values.size() != 100) {
+    values.insert(values.end(), base_values.begin(), base_values.end());
+  }
+  TypeParam m;
+  m.reserve(10);
+  const size_t original_capacity = m.bucket_count();
+  m.insert(values.begin(), values.end());
+  EXPECT_EQ(m.bucket_count(), original_capacity);
+#endif
+}
+
 TYPED_TEST_P(ModifiersTest, Emplace) {
   using T = hash_internal::GeneratedType<TypeParam>;
   T val = hash_internal::Generator<T>()();
@@ -180,8 +210,9 @@ TYPED_TEST_P(ModifiersTest, Swap) {
 // TODO(alkis): Write tests for merge.
 
 REGISTER_TYPED_TEST_CASE_P(ModifiersTest, Clear, Insert, InsertHint,
-                           InsertRange, Emplace, EmplaceHint, Erase, EraseRange,
-                           EraseKey, Swap);
+                           InsertRange, InsertWithinCapacity,
+                           InsertRangeWithinCapacity, Emplace, EmplaceHint,
+                           Erase, EraseRange, EraseKey, Swap);
 
 }  // namespace container_internal
 ABSL_NAMESPACE_END
diff --git a/chromium/third_party/abseil-cpp/absl/copts/configure_copts.bzl b/chromium/third_party/abseil-cpp/absl/copts/configure_copts.bzl
index 669a9060bc8..40d5849a3a6 100644
--- a/chromium/third_party/abseil-cpp/absl/copts/configure_copts.bzl
+++ b/chromium/third_party/abseil-cpp/absl/copts/configure_copts.bzl
@@ -50,6 +50,7 @@ ABSL_RANDOM_RANDEN_COPTS = select({
     ":cpu_x64_windows": ABSL_RANDOM_HWAES_MSVC_X64_FLAGS,
     ":cpu_k8": ABSL_RANDOM_HWAES_X64_FLAGS,
     ":cpu_ppc": ["-mcrypto"],
+    ":cpu_aarch64": ABSL_RANDOM_HWAES_ARM64_FLAGS,
 
     # Supported by default or unsupported.
     "//conditions:default": [],
@@ -70,6 +71,7 @@ def absl_random_randen_copts_init():
         "darwin",
         "x64_windows_msvc",
         "x64_windows",
+        "aarch64",
     ]
     for cpu in cpu_configs:
         native.config_setting(
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/BUILD.bazel b/chromium/third_party/abseil-cpp/absl/debugging/BUILD.bazel
index 5385bcb6509..a8c51a5c8fc 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/BUILD.bazel
+++ b/chromium/third_party/abseil-cpp/absl/debugging/BUILD.bazel
@@ -34,6 +34,7 @@ cc_library(
         "internal/stacktrace_aarch64-inl.inc",
         "internal/stacktrace_arm-inl.inc",
         "internal/stacktrace_config.h",
+        "internal/stacktrace_emscripten-inl.inc",
         "internal/stacktrace_generic-inl.inc",
         "internal/stacktrace_powerpc-inl.inc",
         "internal/stacktrace_unimplemented-inl.inc",
@@ -57,6 +58,7 @@ cc_library(
         "symbolize.cc",
         "symbolize_darwin.inc",
         "symbolize_elf.inc",
+        "symbolize_emscripten.inc",
         "symbolize_unimplemented.inc",
         "symbolize_win32.inc",
     ],
@@ -344,6 +346,7 @@ cc_test(
     srcs = ["internal/stack_consumption_test.cc"],
     copts = ABSL_TEST_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
+    tags = ["notsan"],
     deps = [
         ":stack_consumption",
         "//absl/base:core_headers",
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/BUILD.gn b/chromium/third_party/abseil-cpp/absl/debugging/BUILD.gn
index b941fb94c06..fe01c2b424c 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/absl/debugging/BUILD.gn
@@ -10,6 +10,7 @@ absl_source_set("stacktrace") {
     "internal/stacktrace_aarch64-inl.inc",
     "internal/stacktrace_arm-inl.inc",
     "internal/stacktrace_config.h",
+    "internal/stacktrace_emscripten-inl.inc",
     "internal/stacktrace_generic-inl.inc",
     "internal/stacktrace_powerpc-inl.inc",
     "internal/stacktrace_unimplemented-inl.inc",
@@ -31,6 +32,7 @@ absl_source_set("symbolize") {
     "symbolize.cc",
     "symbolize_darwin.inc",
     "symbolize_elf.inc",
+    "symbolize_emscripten.inc",
     "symbolize_unimplemented.inc",
     "symbolize_win32.inc",
   ]
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/debugging/CMakeLists.txt
index 074b44cf178..760772f3f09 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/debugging/CMakeLists.txt
@@ -22,6 +22,7 @@ absl_cc_library(
     "internal/stacktrace_aarch64-inl.inc"
     "internal/stacktrace_arm-inl.inc"
     "internal/stacktrace_config.h"
+    "internal/stacktrace_emscripten-inl.inc"
     "internal/stacktrace_generic-inl.inc"
     "internal/stacktrace_powerpc-inl.inc"
     "internal/stacktrace_unimplemented-inl.inc"
@@ -48,6 +49,7 @@ absl_cc_library(
     "symbolize.cc"
     "symbolize_darwin.inc"
     "symbolize_elf.inc"
+    "symbolize_emscripten.inc"
     "symbolize_unimplemented.inc"
     "symbolize_win32.inc"
   COPTS
@@ -87,7 +89,7 @@ absl_cc_test(
     absl::memory
     absl::raw_logging_internal
     absl::strings
-    gmock
+    GTest::gmock
 )
 
 absl_cc_library(
@@ -141,7 +143,7 @@ absl_cc_test(
     absl::strings
     absl::raw_logging_internal
     Threads::Threads
-    gmock
+    GTest::gmock
 )
 
 absl_cc_library(
@@ -194,7 +196,7 @@ absl_cc_test(
     absl::core_headers
     absl::memory
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -261,7 +263,7 @@ absl_cc_test(
   DEPS
     absl::leak_check_api_enabled_for_testing
     absl::base
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -275,7 +277,7 @@ absl_cc_test(
   DEPS
     absl::leak_check_api_disabled_for_testing
     absl::base
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -292,7 +294,7 @@ absl_cc_test(
     absl::leak_check_disable
     absl::base
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -322,7 +324,7 @@ absl_cc_test(
     absl::stack_consumption
     absl::core_headers
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 # component target
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_config.h b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_config.h
index cca410d4c75..6cceef26980 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_config.h
+++ b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_config.h
@@ -37,6 +37,10 @@
   "absl/debugging/internal/stacktrace_generic-inl.inc"
 #endif
 
+#elif defined(__EMSCRIPTEN__)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_emscripten-inl.inc"
+
 #elif defined(__linux__) && !defined(__ANDROID__)
 
 #if defined(NO_FRAME_POINTER) && \
@@ -68,7 +72,6 @@
   "absl/debugging/internal/stacktrace_generic-inl.inc"
 #endif
 #endif
-
 #endif
 
 // Fallback to the empty implementation.
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_emscripten-inl.inc b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_emscripten-inl.inc
new file mode 100644
index 00000000000..0f444514386
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_emscripten-inl.inc
@@ -0,0 +1,110 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Portable implementation - just use glibc
+//
+// Note:  The glibc implementation may cause a call to malloc.
+// This can cause a deadlock in HeapProfiler.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_
+
+#include <emscripten.h>
+
+#include <atomic>
+#include <cstring>
+
+#include "absl/base/attributes.h"
+#include "absl/debugging/stacktrace.h"
+
+extern "C" {
+uintptr_t emscripten_stack_snapshot();
+uint32_t emscripten_stack_unwind_buffer(uintptr_t pc, void *buffer,
+                                        uint32_t depth);
+}
+
+// Sometimes, we can try to get a stack trace from within a stack
+// trace, which can cause a self-deadlock.
+// Protect against such reentrant call by failing to get a stack trace.
+//
+// We use __thread here because the code here is extremely low level -- it is
+// called while collecting stack traces from within malloc and mmap, and thus
+// can not call anything which might call malloc or mmap itself.
+static __thread int recursive = 0;
+
+// The stack trace function might be invoked very early in the program's
+// execution (e.g. from the very first malloc).
+// As such, we suppress usage of backtrace during this early stage of execution.
+static std::atomic<bool> disable_stacktraces(true);  // Disabled until healthy.
+// Waiting until static initializers run seems to be late enough.
+// This file is included into stacktrace.cc so this will only run once.
+ABSL_ATTRIBUTE_UNUSED static int stacktraces_enabler = []() {
+  // Check if we can even create stacktraces. If not, bail early and leave
+  // disable_stacktraces set as-is.
+  // clang-format off
+  if (!EM_ASM_INT({ return (typeof wasmOffsetConverter !== 'undefined'); })) {
+    return 0;
+  }
+  // clang-format on
+  disable_stacktraces.store(false, std::memory_order_relaxed);
+  return 0;
+}();
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void **result, int *sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  if (recursive || disable_stacktraces.load(std::memory_order_relaxed)) {
+    return 0;
+  }
+  ++recursive;
+
+  static_cast<void>(ucp);  // Unused.
+  constexpr int kStackLength = 64;
+  void *stack[kStackLength];
+
+  int size;
+  uintptr_t pc = emscripten_stack_snapshot();
+  size = emscripten_stack_unwind_buffer(pc, stack, kStackLength);
+
+  int result_count = size - skip_count;
+  if (result_count < 0) result_count = 0;
+  if (result_count > max_depth) result_count = max_depth;
+  for (int i = 0; i < result_count; i++) result[i] = stack[i + skip_count];
+
+  if (IS_STACK_FRAMES) {
+    // No implementation for finding out the stack frame sizes yet.
+    memset(sizes, 0, sizeof(*sizes) * result_count);
+  }
+  if (min_dropped_frames != nullptr) {
+    if (size - skip_count - max_depth > 0) {
+      *min_dropped_frames = size - skip_count - max_depth;
+    } else {
+      *min_dropped_frames = 0;
+    }
+  }
+
+  --recursive;
+
+  return result_count;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() { return true; }
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_x86-inl.inc b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_x86-inl.inc
index bc320ff75bc..70f79dfcb8f 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_x86-inl.inc
+++ b/chromium/third_party/abseil-cpp/absl/debugging/internal/stacktrace_x86-inl.inc
@@ -132,9 +132,8 @@ static uintptr_t GetFP(const void *vuc) {
     const uintptr_t bp = 0;
     const uintptr_t sp = 0;
 #endif
-    // Sanity-check that the base pointer is valid.  It should be as long as
-    // SHRINK_WRAP_FRAME_POINTER is not set, but it's possible that some code in
-    // the process is compiled with --copt=-fomit-frame-pointer or
+    // Sanity-check that the base pointer is valid. It's possible that some
+    // code in the process is compiled with --copt=-fomit-frame-pointer or
     // --copt=-momit-leaf-frame-pointer.
     //
     // TODO(bcmills): -momit-leaf-frame-pointer is currently the default
@@ -247,7 +246,7 @@ static void **NextStackFrame(void **old_fp, const void *uc) {
   // using an alternate signal stack.
   //
   // TODO(bcmills): The GetFP call should be completely unnecessary when
-  // SHRINK_WRAP_FRAME_POINTER is set (because we should be back in the thread's
+  // ENABLE_COMBINED_UNWINDER is set (because we should be back in the thread's
   // stack by this point), but it is empirically still needed (e.g. when the
   // stack includes a call to abort).  unw_get_reg returns UNW_EBADREG for some
   // frames.  Figure out why GetValidFrameAddr and/or libunwind isn't doing what
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/internal/symbolize.h b/chromium/third_party/abseil-cpp/absl/debugging/internal/symbolize.h
index 4f26130fbb7..8c296f89d50 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/internal/symbolize.h
+++ b/chromium/third_party/abseil-cpp/absl/debugging/internal/symbolize.h
@@ -68,6 +68,12 @@ ABSL_NAMESPACE_END
 #define ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE 1
 #endif
 
+#ifdef ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE
+#error ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE cannot be directly set
+#elif defined(__EMSCRIPTEN__)
+#define ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE 1
+#endif
+
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace debugging_internal {
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/stacktrace.cc b/chromium/third_party/abseil-cpp/absl/debugging/stacktrace.cc
index 1f7c7d82b2d..5358b942867 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/stacktrace.cc
+++ b/chromium/third_party/abseil-cpp/absl/debugging/stacktrace.cc
@@ -49,6 +49,7 @@
 
 # include "absl/debugging/internal/stacktrace_aarch64-inl.inc"
 # include "absl/debugging/internal/stacktrace_arm-inl.inc"
+# include "absl/debugging/internal/stacktrace_emscripten-inl.inc"
 # include "absl/debugging/internal/stacktrace_generic-inl.inc"
 # include "absl/debugging/internal/stacktrace_powerpc-inl.inc"
 # include "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/symbolize.cc b/chromium/third_party/abseil-cpp/absl/debugging/symbolize.cc
index 5e4a25d69dc..f1abdfda592 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/symbolize.cc
+++ b/chromium/third_party/abseil-cpp/absl/debugging/symbolize.cc
@@ -31,6 +31,8 @@
 #include "absl/debugging/symbolize_win32.inc"
 #elif defined(__APPLE__)
 #include "absl/debugging/symbolize_darwin.inc"
+#elif defined(__EMSCRIPTEN__)
+#include "absl/debugging/symbolize_emscripten.inc"
 #else
 #include "absl/debugging/symbolize_unimplemented.inc"
 #endif
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/symbolize_emscripten.inc b/chromium/third_party/abseil-cpp/absl/debugging/symbolize_emscripten.inc
new file mode 100644
index 00000000000..c226c456660
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/debugging/symbolize_emscripten.inc
@@ -0,0 +1,72 @@
+// Copyright 2020 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <cxxabi.h>
+#include <emscripten.h>
+
+#include <algorithm>
+#include <cstring>
+
+#include "absl/base/internal/raw_logging.h"
+#include "absl/debugging/internal/demangle.h"
+#include "absl/strings/numbers.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+
+extern "C" {
+const char* emscripten_pc_get_function(const void* pc);
+}
+
+// clang-format off
+EM_JS(bool, HaveOffsetConverter, (),
+      { return typeof wasmOffsetConverter !== 'undefined'; });
+// clang-format on
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+
+void InitializeSymbolizer(const char*) {
+  if (!HaveOffsetConverter()) {
+    ABSL_RAW_LOG(INFO,
+                 "Symbolization unavailable. Rebuild with -sWASM=1 "
+                 "and -sUSE_OFFSET_CONVERTER=1.");
+  }
+}
+
+bool Symbolize(const void* pc, char* out, int out_size) {
+  // Check if we have the offset converter necessary for pc_get_function.
+  // Without it, the program will abort().
+  if (!HaveOffsetConverter()) {
+    return false;
+  }
+  const char* func_name = emscripten_pc_get_function(pc);
+  if (func_name == nullptr) {
+    return false;
+  }
+
+  strncpy(out, func_name, out_size);
+
+  if (out[out_size - 1] != '\0') {
+    // strncpy() does not '\0' terminate when it truncates.
+    static constexpr char kEllipsis[] = "...";
+    int ellipsis_size = std::min<int>(sizeof(kEllipsis) - 1, out_size - 1);
+    memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size);
+    out[out_size - 1] = '\0';
+  }
+
+  return true;
+}
+
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/debugging/symbolize_test.cc b/chromium/third_party/abseil-cpp/absl/debugging/symbolize_test.cc
index 35de02e24b4..c710a3da812 100644
--- a/chromium/third_party/abseil-cpp/absl/debugging/symbolize_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/debugging/symbolize_test.cc
@@ -146,8 +146,22 @@ static const char *TrySymbolize(void *pc) {
   return TrySymbolizeWithLimit(pc, sizeof(try_symbolize_buffer));
 }
 
-#if defined(ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE) || \
-    defined(ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE)
+#if defined(ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE) ||    \
+    defined(ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE) || \
+    defined(ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE)
+
+// Test with a return address.
+void ABSL_ATTRIBUTE_NOINLINE TestWithReturnAddress() {
+#if defined(ABSL_HAVE_ATTRIBUTE_NOINLINE)
+  void *return_address = __builtin_return_address(0);
+  const char *symbol = TrySymbolize(return_address);
+  ABSL_RAW_CHECK(symbol != nullptr, "TestWithReturnAddress failed");
+  ABSL_RAW_CHECK(strcmp(symbol, "main") == 0, "TestWithReturnAddress failed");
+  std::cout << "TestWithReturnAddress passed" << std::endl;
+#endif
+}
+
+#ifndef ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE
 
 TEST(Symbolize, Cached) {
   // Compilers should give us pointers to them.
@@ -418,6 +432,7 @@ TEST(Symbolize, ForEachSection) {
   close(fd);
 }
 #endif  // !ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE
+#endif  // !ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE
 
 // x86 specific tests.  Uses some inline assembler.
 extern "C" {
@@ -466,17 +481,6 @@ void ABSL_ATTRIBUTE_NOINLINE TestWithPCInsideInlineFunction() {
 }
 }
 
-// Test with a return address.
-void ABSL_ATTRIBUTE_NOINLINE TestWithReturnAddress() {
-#if defined(ABSL_HAVE_ATTRIBUTE_NOINLINE)
-  void *return_address = __builtin_return_address(0);
-  const char *symbol = TrySymbolize(return_address);
-  ABSL_RAW_CHECK(symbol != nullptr, "TestWithReturnAddress failed");
-  ABSL_RAW_CHECK(strcmp(symbol, "main") == 0, "TestWithReturnAddress failed");
-  std::cout << "TestWithReturnAddress passed" << std::endl;
-#endif
-}
-
 #if defined(__arm__) && ABSL_HAVE_ATTRIBUTE(target)
 // Test that we correctly identify bounds of Thumb functions on ARM.
 //
@@ -559,7 +563,6 @@ TEST(Symbolize, SymbolizeWithDemangling) {
 
 #endif  // !defined(ABSL_CONSUME_DLL)
 #else  // Symbolizer unimplemented
-
 TEST(Symbolize, Unimplemented) {
   char buf[64];
   EXPECT_FALSE(absl::Symbolize((void *)(&nonstatic_func), buf, sizeof(buf)));
diff --git a/chromium/third_party/abseil-cpp/absl/flags/BUILD.bazel b/chromium/third_party/abseil-cpp/absl/flags/BUILD.bazel
index 147249ed1bb..c178b86b4ef 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/BUILD.bazel
+++ b/chromium/third_party/abseil-cpp/absl/flags/BUILD.bazel
@@ -259,6 +259,7 @@ cc_library(
         ":reflection",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/container:flat_hash_map",
         "//absl/strings",
     ],
 )
diff --git a/chromium/third_party/abseil-cpp/absl/flags/BUILD.gn b/chromium/third_party/abseil-cpp/absl/flags/BUILD.gn
index 0a87d9c36c8..a47248b97ab 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/absl/flags/BUILD.gn
@@ -172,6 +172,7 @@ absl_source_set("usage_internal") {
     ":reflection",
     "//third_party/abseil-cpp/absl/base:config",
     "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/container:flat_hash_map",
     "//third_party/abseil-cpp/absl/strings",
   ]
   visibility = [ ":*" ]
diff --git a/chromium/third_party/abseil-cpp/absl/flags/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/flags/CMakeLists.txt
index caac69cf891..956f70f868c 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/flags/CMakeLists.txt
@@ -239,6 +239,7 @@ absl_cc_library(
     absl::flags_private_handle_accessor
     absl::flags_program_name
     absl::flags_reflection
+    absl::flat_hash_map
     absl::strings
     absl::synchronization
 )
@@ -309,7 +310,7 @@ absl_cc_test(
     absl::flags_reflection
     absl::memory
     absl::strings
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -321,7 +322,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::flags_config
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -341,7 +342,7 @@ absl_cc_test(
     absl::flags_reflection
     absl::strings
     absl::time
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -353,7 +354,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::flags_marshalling
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -372,7 +373,7 @@ absl_cc_test(
     absl::scoped_set_env
     absl::span
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -384,7 +385,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::flags_path_util
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -397,7 +398,7 @@ absl_cc_test(
   DEPS
     absl::flags_program_name
     absl::strings
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -414,7 +415,7 @@ absl_cc_test(
     absl::flags_usage
     absl::memory
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -428,7 +429,7 @@ absl_cc_test(
     absl::base
     absl::flags_internal
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -443,7 +444,7 @@ absl_cc_test(
     absl::flags_path_util
     absl::flags_program_name
     absl::strings
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -462,5 +463,5 @@ absl_cc_test(
     absl::flags_reflection
     absl::flags_usage
     absl::strings
-    gtest
+    GTest::gtest
 )
diff --git a/chromium/third_party/abseil-cpp/absl/flags/flag_benchmark.cc b/chromium/third_party/abseil-cpp/absl/flags/flag_benchmark.cc
index 57584f85d35..fc572d9ce32 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/flag_benchmark.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/flag_benchmark.cc
@@ -101,7 +101,39 @@ std::string AbslUnparseFlag(const UDT&) { return ""; }
   A(AbslDuration)            \
   A(UDT)
 
-#define FLAG_DEF(T) ABSL_FLAG(T, T##_flag, {}, "");
+#define REPLICATE_0(A, T, name, index) A(T, name, index)
+#define REPLICATE_1(A, T, name, index) \
+  REPLICATE_0(A, T, name, index##0) REPLICATE_0(A, T, name, index##1)
+#define REPLICATE_2(A, T, name, index) \
+  REPLICATE_1(A, T, name, index##0) REPLICATE_1(A, T, name, index##1)
+#define REPLICATE_3(A, T, name, index) \
+  REPLICATE_2(A, T, name, index##0) REPLICATE_2(A, T, name, index##1)
+#define REPLICATE_4(A, T, name, index) \
+  REPLICATE_3(A, T, name, index##0) REPLICATE_3(A, T, name, index##1)
+#define REPLICATE_5(A, T, name, index) \
+  REPLICATE_4(A, T, name, index##0) REPLICATE_4(A, T, name, index##1)
+#define REPLICATE_6(A, T, name, index) \
+  REPLICATE_5(A, T, name, index##0) REPLICATE_5(A, T, name, index##1)
+#define REPLICATE_7(A, T, name, index) \
+  REPLICATE_6(A, T, name, index##0) REPLICATE_6(A, T, name, index##1)
+#define REPLICATE_8(A, T, name, index) \
+  REPLICATE_7(A, T, name, index##0) REPLICATE_7(A, T, name, index##1)
+#define REPLICATE_9(A, T, name, index) \
+  REPLICATE_8(A, T, name, index##0) REPLICATE_8(A, T, name, index##1)
+#if defined(_MSC_VER)
+#define REPLICATE(A, T, name) \
+  REPLICATE_7(A, T, name, 0) REPLICATE_7(A, T, name, 1)
+#define SINGLE_FLAG(T) FLAGS_##T##_flag_00000000
+#else
+#define REPLICATE(A, T, name) \
+  REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1)
+#define SINGLE_FLAG(T) FLAGS_##T##_flag_0000000000
+#endif
+#define REPLICATE_ALL(A, T, name) \
+  REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1)
+
+#define COUNT(T, name, index) +1
+constexpr size_t kNumFlags = 0 REPLICATE(COUNT, _, _);
 
 #if defined(__clang__) && defined(__linux__)
 // Force the flags used for benchmarks into a separate ELF section.
@@ -110,38 +142,87 @@ std::string AbslUnparseFlag(const UDT&) { return ""; }
 // benchmark results more reproducible across unrelated code changes.
 #pragma clang section data = ".benchmark_flags"
 #endif
+#define DEFINE_FLAG(T, name, index) ABSL_FLAG(T, name##_##index, {}, "");
+#define FLAG_DEF(T) REPLICATE(DEFINE_FLAG, T, T##_flag);
 BENCHMARKED_TYPES(FLAG_DEF)
 #if defined(__clang__) && defined(__linux__)
 #pragma clang section data = ""
 #endif
 // Register thousands of flags to bloat up the size of the registry.
 // This mimics real life production binaries.
-#define DEFINE_FLAG_0(name) ABSL_FLAG(int, name, 0, "");
-#define DEFINE_FLAG_1(name) DEFINE_FLAG_0(name##0) DEFINE_FLAG_0(name##1)
-#define DEFINE_FLAG_2(name) DEFINE_FLAG_1(name##0) DEFINE_FLAG_1(name##1)
-#define DEFINE_FLAG_3(name) DEFINE_FLAG_2(name##0) DEFINE_FLAG_2(name##1)
-#define DEFINE_FLAG_4(name) DEFINE_FLAG_3(name##0) DEFINE_FLAG_3(name##1)
-#define DEFINE_FLAG_5(name) DEFINE_FLAG_4(name##0) DEFINE_FLAG_4(name##1)
-#define DEFINE_FLAG_6(name) DEFINE_FLAG_5(name##0) DEFINE_FLAG_5(name##1)
-#define DEFINE_FLAG_7(name) DEFINE_FLAG_6(name##0) DEFINE_FLAG_6(name##1)
-#define DEFINE_FLAG_8(name) DEFINE_FLAG_7(name##0) DEFINE_FLAG_7(name##1)
-#define DEFINE_FLAG_9(name) DEFINE_FLAG_8(name##0) DEFINE_FLAG_8(name##1)
-#define DEFINE_FLAG_10(name) DEFINE_FLAG_9(name##0) DEFINE_FLAG_9(name##1)
-#define DEFINE_FLAG_11(name) DEFINE_FLAG_10(name##0) DEFINE_FLAG_10(name##1)
-#define DEFINE_FLAG_12(name) DEFINE_FLAG_11(name##0) DEFINE_FLAG_11(name##1)
-DEFINE_FLAG_12(bloat_flag_);
+#define BLOAT_FLAG(_unused1, _unused2, index) \
+  ABSL_FLAG(int, bloat_flag_##index, 0, "");
+REPLICATE_ALL(BLOAT_FLAG, _, _)
 
 namespace {
 
-#define BM_GetFlag(T)                                            \
-  void BM_GetFlag_##T(benchmark::State& state) {                 \
-    for (auto _ : state) {                                       \
-      benchmark::DoNotOptimize(absl::GetFlag(FLAGS_##T##_flag)); \
-    }                                                            \
-  }                                                              \
-  BENCHMARK(BM_GetFlag_##T)->ThreadRange(1, 16);
+#define FLAG_PTR(T, name, index) &FLAGS_##name##_##index,
+#define FLAG_PTR_ARR(T)                              \
+  static constexpr absl::Flag<T>* FlagPtrs_##T[] = { \
+      REPLICATE(FLAG_PTR, T, T##_flag)};
+BENCHMARKED_TYPES(FLAG_PTR_ARR)
+
+#define BM_SingleGetFlag(T)                                    \
+  void BM_SingleGetFlag_##T(benchmark::State& state) {         \
+    for (auto _ : state) {                                     \
+      benchmark::DoNotOptimize(absl::GetFlag(SINGLE_FLAG(T))); \
+    }                                                          \
+  }                                                            \
+  BENCHMARK(BM_SingleGetFlag_##T)->ThreadRange(1, 16);
+
+BENCHMARKED_TYPES(BM_SingleGetFlag)
+
+template <typename T>
+struct Accumulator {
+  using type = T;
+};
+template <>
+struct Accumulator<String> {
+  using type = size_t;
+};
+template <>
+struct Accumulator<VectorOfStrings> {
+  using type = size_t;
+};
+template <>
+struct Accumulator<OptionalInt> {
+  using type = bool;
+};
+template <>
+struct Accumulator<OptionalString> {
+  using type = bool;
+};
+template <>
+struct Accumulator<UDT> {
+  using type = bool;
+};
+
+template <typename T>
+void Accumulate(typename Accumulator<T>::type& a, const T& f) {
+  a += f;
+}
+void Accumulate(bool& a, bool f) { a = a || f; }
+void Accumulate(size_t& a, const std::string& f) { a += f.size(); }
+void Accumulate(size_t& a, const std::vector<std::string>& f) { a += f.size(); }
+void Accumulate(bool& a, const OptionalInt& f) { a |= f.has_value(); }
+void Accumulate(bool& a, const OptionalString& f) { a |= f.has_value(); }
+void Accumulate(bool& a, const UDT& f) {
+  a |= reinterpret_cast<int64_t>(&f) & 0x1;
+}
+
+#define BM_ManyGetFlag(T)                            \
+  void BM_ManyGetFlag_##T(benchmark::State& state) { \
+    Accumulator<T>::type res = {};                   \
+    while (state.KeepRunningBatch(kNumFlags)) {      \
+      for (auto* flag_ptr : FlagPtrs_##T) {          \
+        Accumulate(res, absl::GetFlag(*flag_ptr));   \
+      }                                              \
+    }                                                \
+    benchmark::DoNotOptimize(res);                   \
+  }                                                  \
+  BENCHMARK(BM_ManyGetFlag_##T)->ThreadRange(1, 8);
 
-BENCHMARKED_TYPES(BM_GetFlag)
+BENCHMARKED_TYPES(BM_ManyGetFlag)
 
 void BM_ThreadedFindCommandLineFlag(benchmark::State& state) {
   char dummy[] = "dummy";
@@ -150,17 +231,18 @@ void BM_ThreadedFindCommandLineFlag(benchmark::State& state) {
   // is finalized.
   absl::ParseCommandLine(1, argv);
 
-  for (auto s : state) {
-    benchmark::DoNotOptimize(
-        absl::FindCommandLineFlag("bloat_flag_010101010101"));
+  while (state.KeepRunningBatch(kNumFlags)) {
+    for (auto* flag_ptr : FlagPtrs_bool) {
+      benchmark::DoNotOptimize(absl::FindCommandLineFlag(flag_ptr->Name()));
+    }
   }
 }
 BENCHMARK(BM_ThreadedFindCommandLineFlag)->ThreadRange(1, 16);
 
 }  // namespace
 
-#define InvokeGetFlag(T)                                               \
-  T AbslInvokeGetFlag##T() { return absl::GetFlag(FLAGS_##T##_flag); } \
+#define InvokeGetFlag(T)                                             \
+  T AbslInvokeGetFlag##T() { return absl::GetFlag(SINGLE_FLAG(T)); } \
   int odr##T = (benchmark::DoNotOptimize(AbslInvokeGetFlag##T), 1);
 
 BENCHMARKED_TYPES(InvokeGetFlag)
diff --git a/chromium/third_party/abseil-cpp/absl/flags/flag_test.cc b/chromium/third_party/abseil-cpp/absl/flags/flag_test.cc
index 6912b5461f1..ba81317bc60 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/flag_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/flag_test.cc
@@ -61,6 +61,7 @@ void TestCallback() {}
 struct UDT {
   UDT() = default;
   UDT(const UDT&) = default;
+  UDT& operator=(const UDT&) = default;
 };
 bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; }
 std::string AbslUnparseFlag(const UDT&) { return ""; }
diff --git a/chromium/third_party/abseil-cpp/absl/flags/internal/sequence_lock.h b/chromium/third_party/abseil-cpp/absl/flags/internal/sequence_lock.h
index 807b2a73137..36318ab9d36 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/internal/sequence_lock.h
+++ b/chromium/third_party/abseil-cpp/absl/flags/internal/sequence_lock.h
@@ -49,7 +49,7 @@ inline constexpr size_t AlignUp(size_t x, size_t align) {
 // The memory reads and writes protected by this lock must use the provided
 // `TryRead()` and `Write()` functions. These functions behave similarly to
 // `memcpy()`, with one oddity: the protected data must be an array of
-// `std::atomic<int64>`. This is to comply with the C++ standard, which
+// `std::atomic<uint64>`. This is to comply with the C++ standard, which
 // considers data races on non-atomic objects to be undefined behavior. See "Can
 // Seqlocks Get Along With Programming Language Memory Models?"[1] by Hans J.
 // Boehm for more details.
diff --git a/chromium/third_party/abseil-cpp/absl/flags/internal/usage.cc b/chromium/third_party/abseil-cpp/absl/flags/internal/usage.cc
index a588c7f73ac..a883567fb47 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/internal/usage.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/internal/usage.cc
@@ -17,6 +17,7 @@
 
 #include <stdint.h>
 
+#include <algorithm>
 #include <functional>
 #include <map>
 #include <ostream>
@@ -245,7 +246,7 @@ void FlagsHelpImpl(std::ostream& out, PerFlagFilter filter_cb,
         << XMLElement("usage", program_usage_message) << '\n';
   }
 
-  // Map of package name to
+  // Ordered map of package name to
   //   map of file name to
   //     vector of flags in the file.
   // This map is used to output matching flags grouped by package and file
@@ -255,9 +256,6 @@ void FlagsHelpImpl(std::ostream& out, PerFlagFilter filter_cb,
       matching_flags;
 
   flags_internal::ForEachFlag([&](absl::CommandLineFlag& flag) {
-    // Ignore retired flags.
-    if (flag.IsRetired()) return;
-
     // If the flag has been stripped, pretend that it doesn't exist.
     if (flag.Help() == flags_internal::kStrippedFlagHelp) return;
 
@@ -273,20 +271,34 @@ void FlagsHelpImpl(std::ostream& out, PerFlagFilter filter_cb,
 
   absl::string_view package_separator;  // controls blank lines between packages
   absl::string_view file_separator;     // controls blank lines between files
-  for (const auto& package : matching_flags) {
+  for (auto& package : matching_flags) {
     if (format == HelpFormat::kHumanReadable) {
+      // Hide packages with only retired flags
+      bool all_package_flags_are_retired = true;
+      for (const auto& flags_in_file : package.second) {
+        for (const auto* flag : flags_in_file.second) {
+          all_package_flags_are_retired &= flag->IsRetired();
+        }
+      }
+      if (all_package_flags_are_retired) continue;
       out << package_separator;
       package_separator = "\n\n";
     }
 
     file_separator = "";
-    for (const auto& flags_in_file : package.second) {
+    for (auto& flags_in_file : package.second) {
       if (format == HelpFormat::kHumanReadable) {
         out << file_separator << "  Flags from " << flags_in_file.first
             << ":\n";
         file_separator = "\n";
       }
 
+      std::sort(std::begin(flags_in_file.second),
+                std::end(flags_in_file.second),
+                [](const CommandLineFlag* lhs, const CommandLineFlag* rhs) {
+                  return lhs->Name() < rhs->Name();
+                });
+
       for (const auto* flag : flags_in_file.second) {
         flags_internal::FlagHelp(out, *flag, format);
       }
@@ -328,8 +340,11 @@ void FlagsHelpImpl(std::ostream& out,
 // Produces the help message describing specific flag.
 void FlagHelp(std::ostream& out, const CommandLineFlag& flag,
               HelpFormat format) {
-  if (format == HelpFormat::kHumanReadable)
+  if (format == HelpFormat::kHumanReadable) {
+    // Ignore retired flags
+    if (flag.IsRetired()) return;
     flags_internal::FlagHelpHumanReadable(flag, out);
+  }
 }
 
 // --------------------------------------------------------------------
diff --git a/chromium/third_party/abseil-cpp/absl/flags/internal/usage_test.cc b/chromium/third_party/abseil-cpp/absl/flags/internal/usage_test.cc
index b5c2487da57..5055640a5d3 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/internal/usage_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/internal/usage_test.cc
@@ -45,6 +45,7 @@ static const char kTestUsageMessage[] = "Custom usage message";
 struct UDT {
   UDT() = default;
   UDT(const UDT&) = default;
+  UDT& operator=(const UDT&) = default;
 };
 bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; }
 std::string AbslUnparseFlag(const UDT&) { return "UDT{}"; }
@@ -60,6 +61,9 @@ ABSL_FLAG(
     "Even more long long long long long long long long long long long long "
     "help message.");
 
+ABSL_RETIRED_FLAG(int64_t, usage_reporting_test_flag_07, 1,
+                  "usage_reporting_test_flag_07 help message");
+
 namespace {
 
 namespace flags = absl::flags_internal;
diff --git a/chromium/third_party/abseil-cpp/absl/flags/parse_test.cc b/chromium/third_party/abseil-cpp/absl/flags/parse_test.cc
index 41bc0bc6b3a..8dc91db2b3d 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/parse_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/parse_test.cc
@@ -46,6 +46,7 @@ using absl::base_internal::ScopedSetEnv;
 struct UDT {
   UDT() = default;
   UDT(const UDT&) = default;
+  UDT& operator=(const UDT&) = default;
   UDT(int v) : value(v) {}  // NOLINT
 
   int value;
diff --git a/chromium/third_party/abseil-cpp/absl/flags/reflection.cc b/chromium/third_party/abseil-cpp/absl/flags/reflection.cc
index 0c761101633..dbce4032ab6 100644
--- a/chromium/third_party/abseil-cpp/absl/flags/reflection.cc
+++ b/chromium/third_party/abseil-cpp/absl/flags/reflection.cc
@@ -18,11 +18,11 @@
 #include <assert.h>
 
 #include <atomic>
-#include <map>
 #include <string>
 
 #include "absl/base/config.h"
 #include "absl/base/thread_annotations.h"
+#include "absl/container/flat_hash_map.h"
 #include "absl/flags/commandlineflag.h"
 #include "absl/flags/internal/private_handle_accessor.h"
 #include "absl/flags/internal/registry.h"
@@ -68,7 +68,7 @@ class FlagRegistry {
   friend void FinalizeRegistry();
 
   // The map from name to flag, for FindFlag().
-  using FlagMap = std::map<absl::string_view, CommandLineFlag*>;
+  using FlagMap = absl::flat_hash_map<absl::string_view, CommandLineFlag*>;
   using FlagIterator = FlagMap::iterator;
   using FlagConstIterator = FlagMap::const_iterator;
   FlagMap flags_;
@@ -204,6 +204,10 @@ void FinalizeRegistry() {
   for (const auto& f : registry.flags_) {
     registry.flat_flags_.push_back(f.second);
   }
+  std::sort(std::begin(registry.flat_flags_), std::end(registry.flat_flags_),
+            [](const CommandLineFlag* lhs, const CommandLineFlag* rhs) {
+              return lhs->Name() < rhs->Name();
+            });
   registry.flags_.clear();
   registry.finalized_flags_.store(true, std::memory_order_release);
 }
diff --git a/chromium/third_party/abseil-cpp/absl/functional/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/functional/CMakeLists.txt
index cda914f2cd5..3919e9a1def 100644
--- a/chromium/third_party/abseil-cpp/absl/functional/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/functional/CMakeLists.txt
@@ -39,7 +39,7 @@ absl_cc_test(
   DEPS
     absl::bind_front
     absl::memory
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -68,5 +68,5 @@ absl_cc_test(
     absl::function_ref
     absl::memory
     absl::test_instance_tracker
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/functional/function_ref.h b/chromium/third_party/abseil-cpp/absl/functional/function_ref.h
index 6e03ac2e04e..5790a652518 100644
--- a/chromium/third_party/abseil-cpp/absl/functional/function_ref.h
+++ b/chromium/third_party/abseil-cpp/absl/functional/function_ref.h
@@ -122,6 +122,7 @@ class FunctionRef<R(Args...)> {
   // To help prevent subtle lifetime bugs, FunctionRef is not assignable.
   // Typically, it should only be used as an argument type.
   FunctionRef& operator=(const FunctionRef& rhs) = delete;
+  FunctionRef(const FunctionRef& rhs) = default;
 
   // Call the underlying object.
   R operator()(Args... args) const {
diff --git a/chromium/third_party/abseil-cpp/absl/hash/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/hash/CMakeLists.txt
index b43bfa542f0..c82f66f02c0 100644
--- a/chromium/third_party/abseil-cpp/absl/hash/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/hash/CMakeLists.txt
@@ -52,7 +52,7 @@ absl_cc_library(
     absl::meta
     absl::strings
     absl::variant
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -72,7 +72,7 @@ absl_cc_test(
     absl::spy_hash_state
     absl::meta
     absl::int128
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -113,7 +113,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::city
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -141,5 +141,5 @@ absl_cc_test(
   DEPS
     absl::wyhash
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/hash/hash.h b/chromium/third_party/abseil-cpp/absl/hash/hash.h
index 69c44fde49b..8282ea53c65 100644
--- a/chromium/third_party/abseil-cpp/absl/hash/hash.h
+++ b/chromium/third_party/abseil-cpp/absl/hash/hash.h
@@ -230,7 +230,7 @@ using Hash = absl::hash_internal::Hash<T>;
 // The requirement that the arguments match in both type and value is critical.
 // It means that `a == b` does not necessarily imply `HashOf(a) == HashOf(b)` if
 // `a` and `b` have different types. For example, `HashOf(2) != HashOf(2.0)`.
-template <typename... Types>
+template <int&... ExplicitArgumentBarrier, typename... Types>
 size_t HashOf(const Types&... values) {
   auto tuple = std::tie(values...);
   return absl::Hash<decltype(tuple)>{}(tuple);
diff --git a/chromium/third_party/abseil-cpp/absl/hash/hash_test.cc b/chromium/third_party/abseil-cpp/absl/hash/hash_test.cc
index 02b7733d8d7..b3ddebdd42e 100644
--- a/chromium/third_party/abseil-cpp/absl/hash/hash_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/hash/hash_test.cc
@@ -995,4 +995,17 @@ TEST(HashOf, MatchesHashOfTupleForMultipleArguments) {
             absl::HashOf(std::make_tuple(hello, world)));
 }
 
+template <typename T>
+std::true_type HashOfExplicitParameter(decltype(absl::HashOf<T>(0))) {
+  return {};
+}
+template <typename T>
+std::false_type HashOfExplicitParameter(size_t) {
+  return {};
+}
+
+TEST(HashOf, CantPassExplicitTemplateParameters) {
+  EXPECT_FALSE(HashOfExplicitParameter<int>(0));
+}
+
 }  // namespace
diff --git a/chromium/third_party/abseil-cpp/absl/hash/internal/hash.h b/chromium/third_party/abseil-cpp/absl/hash/internal/hash.h
index 69dbbc6ba09..90627e001b5 100644
--- a/chromium/third_party/abseil-cpp/absl/hash/internal/hash.h
+++ b/chromium/third_party/abseil-cpp/absl/hash/internal/hash.h
@@ -856,8 +856,15 @@ class ABSL_DLL MixingHashState : public HashStateBase<MixingHashState> {
   }
 
   ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Mix(uint64_t state, uint64_t v) {
+#if defined(__aarch64__)
+    // On AArch64, calculating a 128-bit product is inefficient, because it
+    // requires a sequence of two instructions to calculate the upper and lower
+    // halves of the result.
+    using MultType = uint64_t;
+#else
     using MultType =
         absl::conditional_t<sizeof(size_t) == 4, uint64_t, uint128>;
+#endif
     // We do the addition in 64-bit space to make sure the 128-bit
     // multiplication is fast. If we were to do it as MultType the compiler has
     // to assume that the high word is non-zero and needs to perform 2
diff --git a/chromium/third_party/abseil-cpp/absl/memory/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/memory/CMakeLists.txt
index 78fb7e1b316..9d50e1dcd4c 100644
--- a/chromium/third_party/abseil-cpp/absl/memory/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/memory/CMakeLists.txt
@@ -37,7 +37,7 @@ absl_cc_test(
   DEPS
     absl::memory
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -51,5 +51,5 @@ absl_cc_test(
     absl::memory
     absl::config
     absl::exception_safety_testing
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/meta/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/meta/CMakeLists.txt
index 672ead2fd0a..9de4bd37514 100644
--- a/chromium/third_party/abseil-cpp/absl/meta/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/meta/CMakeLists.txt
@@ -35,7 +35,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 # component target
diff --git a/chromium/third_party/abseil-cpp/absl/numeric/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/numeric/CMakeLists.txt
index 781987dc883..26df5cf703d 100644
--- a/chromium/third_party/abseil-cpp/absl/numeric/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/numeric/CMakeLists.txt
@@ -38,7 +38,7 @@ absl_cc_test(
     absl::bits
     absl::core_headers
     absl::random_random
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -73,7 +73,7 @@ absl_cc_test(
     absl::core_headers
     absl::hash_testing
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 # component target
diff --git a/chromium/third_party/abseil-cpp/absl/numeric/int128.cc b/chromium/third_party/abseil-cpp/absl/numeric/int128.cc
index 5160df793ea..17d88744ae1 100644
--- a/chromium/third_party/abseil-cpp/absl/numeric/int128.cc
+++ b/chromium/third_party/abseil-cpp/absl/numeric/int128.cc
@@ -138,28 +138,21 @@ uint128::uint128(float v) : uint128(MakeUint128FromFloat(v)) {}
 uint128::uint128(double v) : uint128(MakeUint128FromFloat(v)) {}
 uint128::uint128(long double v) : uint128(MakeUint128FromFloat(v)) {}
 
+#if !defined(ABSL_HAVE_INTRINSIC_INT128)
 uint128 operator/(uint128 lhs, uint128 rhs) {
-#if defined(ABSL_HAVE_INTRINSIC_INT128)
-  return static_cast<unsigned __int128>(lhs) /
-         static_cast<unsigned __int128>(rhs);
-#else  // ABSL_HAVE_INTRINSIC_INT128
   uint128 quotient = 0;
   uint128 remainder = 0;
   DivModImpl(lhs, rhs, &quotient, &remainder);
   return quotient;
-#endif  // ABSL_HAVE_INTRINSIC_INT128
 }
+
 uint128 operator%(uint128 lhs, uint128 rhs) {
-#if defined(ABSL_HAVE_INTRINSIC_INT128)
-  return static_cast<unsigned __int128>(lhs) %
-         static_cast<unsigned __int128>(rhs);
-#else  // ABSL_HAVE_INTRINSIC_INT128
   uint128 quotient = 0;
   uint128 remainder = 0;
   DivModImpl(lhs, rhs, &quotient, &remainder);
   return remainder;
-#endif  // ABSL_HAVE_INTRINSIC_INT128
 }
+#endif  // !defined(ABSL_HAVE_INTRINSIC_INT128)
 
 namespace {
 
diff --git a/chromium/third_party/abseil-cpp/absl/numeric/int128.h b/chromium/third_party/abseil-cpp/absl/numeric/int128.h
index 235361a8237..a9cbe489dd1 100644
--- a/chromium/third_party/abseil-cpp/absl/numeric/int128.h
+++ b/chromium/third_party/abseil-cpp/absl/numeric/int128.h
@@ -18,6 +18,10 @@
 // -----------------------------------------------------------------------------
 //
 // This header file defines 128-bit integer types, `uint128` and `int128`.
+//
+// TODO(absl-team): This module is inconsistent as many inline `uint128` methods
+// are defined in this file, while many inline `int128` methods are defined in
+// the `int128_*_intrinsic.inc` files.
 
 #ifndef ABSL_NUMERIC_INT128_H_
 #define ABSL_NUMERIC_INT128_H_
@@ -783,8 +787,13 @@ inline uint128::operator long double() const {
 // Comparison operators.
 
 inline bool operator==(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) ==
+         static_cast<unsigned __int128>(rhs);
+#else
   return (Uint128Low64(lhs) == Uint128Low64(rhs) &&
           Uint128High64(lhs) == Uint128High64(rhs));
+#endif
 }
 
 inline bool operator!=(uint128 lhs, uint128 rhs) {
@@ -810,53 +819,85 @@ inline bool operator>=(uint128 lhs, uint128 rhs) { return !(lhs < rhs); }
 
 // Unary operators.
 
+constexpr inline uint128 operator+(uint128 val) {
+  return val;
+}
+
+constexpr inline int128 operator+(int128 val) {
+  return val;
+}
+
 inline uint128 operator-(uint128 val) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return -static_cast<unsigned __int128>(val);
+#else
   uint64_t hi = ~Uint128High64(val);
   uint64_t lo = ~Uint128Low64(val) + 1;
   if (lo == 0) ++hi;  // carry
   return MakeUint128(hi, lo);
+#endif
 }
 
 constexpr inline bool operator!(uint128 val) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return !static_cast<unsigned __int128>(val);
+#else
   return !Uint128High64(val) && !Uint128Low64(val);
+#endif
 }
 
 // Logical operators.
 
 constexpr inline uint128 operator~(uint128 val) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return ~static_cast<unsigned __int128>(val);
+#else
   return MakeUint128(~Uint128High64(val), ~Uint128Low64(val));
+#endif
 }
 
 constexpr inline uint128 operator|(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) |
+         static_cast<unsigned __int128>(rhs);
+#else
   return MakeUint128(Uint128High64(lhs) | Uint128High64(rhs),
-                           Uint128Low64(lhs) | Uint128Low64(rhs));
+                     Uint128Low64(lhs) | Uint128Low64(rhs));
+#endif
 }
 
 constexpr inline uint128 operator&(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) &
+         static_cast<unsigned __int128>(rhs);
+#else
   return MakeUint128(Uint128High64(lhs) & Uint128High64(rhs),
-                           Uint128Low64(lhs) & Uint128Low64(rhs));
+                     Uint128Low64(lhs) & Uint128Low64(rhs));
+#endif
 }
 
 constexpr inline uint128 operator^(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) ^
+         static_cast<unsigned __int128>(rhs);
+#else
   return MakeUint128(Uint128High64(lhs) ^ Uint128High64(rhs),
-                           Uint128Low64(lhs) ^ Uint128Low64(rhs));
+                     Uint128Low64(lhs) ^ Uint128Low64(rhs));
+#endif
 }
 
 inline uint128& uint128::operator|=(uint128 other) {
-  hi_ |= other.hi_;
-  lo_ |= other.lo_;
+  *this = *this | other;
   return *this;
 }
 
 inline uint128& uint128::operator&=(uint128 other) {
-  hi_ &= other.hi_;
-  lo_ &= other.lo_;
+  *this = *this & other;
   return *this;
 }
 
 inline uint128& uint128::operator^=(uint128 other) {
-  hi_ ^= other.hi_;
-  lo_ ^= other.lo_;
+  *this = *this ^ other;
   return *this;
 }
 
@@ -899,21 +940,31 @@ inline uint128 operator>>(uint128 lhs, int amount) {
 }
 
 inline uint128 operator+(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) +
+         static_cast<unsigned __int128>(rhs);
+#else
   uint128 result = MakeUint128(Uint128High64(lhs) + Uint128High64(rhs),
                                Uint128Low64(lhs) + Uint128Low64(rhs));
   if (Uint128Low64(result) < Uint128Low64(lhs)) {  // check for carry
     return MakeUint128(Uint128High64(result) + 1, Uint128Low64(result));
   }
   return result;
+#endif
 }
 
 inline uint128 operator-(uint128 lhs, uint128 rhs) {
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+  return static_cast<unsigned __int128>(lhs) -
+         static_cast<unsigned __int128>(rhs);
+#else
   uint128 result = MakeUint128(Uint128High64(lhs) - Uint128High64(rhs),
                                Uint128Low64(lhs) - Uint128Low64(rhs));
   if (Uint128Low64(lhs) < Uint128Low64(rhs)) {  // check for carry
     return MakeUint128(Uint128High64(result) - 1, Uint128Low64(result));
   }
   return result;
+#endif
 }
 
 inline uint128 operator*(uint128 lhs, uint128 rhs) {
@@ -943,6 +994,18 @@ inline uint128 operator*(uint128 lhs, uint128 rhs) {
 #endif  // ABSL_HAVE_INTRINSIC128
 }
 
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+inline uint128 operator/(uint128 lhs, uint128 rhs) {
+  return static_cast<unsigned __int128>(lhs) /
+         static_cast<unsigned __int128>(rhs);
+}
+
+inline uint128 operator%(uint128 lhs, uint128 rhs) {
+  return static_cast<unsigned __int128>(lhs) %
+         static_cast<unsigned __int128>(rhs);
+}
+#endif
+
 // Increment/decrement operators.
 
 inline uint128 uint128::operator++(int) {
diff --git a/chromium/third_party/abseil-cpp/absl/numeric/int128_test.cc b/chromium/third_party/abseil-cpp/absl/numeric/int128_test.cc
index bc86c714acc..c445d89a991 100644
--- a/chromium/third_party/abseil-cpp/absl/numeric/int128_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/numeric/int128_test.cc
@@ -226,6 +226,11 @@ TEST(Uint128, AllTests) {
   EXPECT_EQ(test >>= 1, one);
   EXPECT_EQ(test <<= 1, two);
 
+  EXPECT_EQ(big, +big);
+  EXPECT_EQ(two, +two);
+  EXPECT_EQ(absl::Uint128Max(), +absl::Uint128Max());
+  EXPECT_EQ(zero, +zero);
+
   EXPECT_EQ(big, -(-big));
   EXPECT_EQ(two, -((-one) - 1));
   EXPECT_EQ(absl::Uint128Max(), -one);
@@ -769,6 +774,19 @@ TEST(Int128, ComparisonTest) {
   }
 }
 
+TEST(Int128, UnaryPlusTest) {
+  int64_t values64[] = {0, 1, 12345, 0x4000000000000000,
+                        std::numeric_limits<int64_t>::max()};
+  for (int64_t value : values64) {
+    SCOPED_TRACE(::testing::Message() << "value = " << value);
+
+    EXPECT_EQ(absl::int128(value), +absl::int128(value));
+    EXPECT_EQ(absl::int128(-value), +absl::int128(-value));
+    EXPECT_EQ(absl::MakeInt128(value, 0), +absl::MakeInt128(value, 0));
+    EXPECT_EQ(absl::MakeInt128(-value, 0), +absl::MakeInt128(-value, 0));
+  }
+}
+
 TEST(Int128, UnaryNegationTest) {
   int64_t values64[] = {0, 1, 12345, 0x4000000000000000,
                         std::numeric_limits<int64_t>::max()};
diff --git a/chromium/third_party/abseil-cpp/absl/random/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/random/CMakeLists.txt
index 3009a0348a3..9d1c67fb33c 100644
--- a/chromium/third_party/abseil-cpp/absl/random/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/random/CMakeLists.txt
@@ -62,8 +62,8 @@ absl_cc_test(
     absl::random_random
     absl::random_internal_sequence_urbg
     absl::fast_type_id
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -119,8 +119,8 @@ absl_cc_library(
     absl::type_traits
     absl::utility
     absl::variant
-    gmock
-    gtest
+    GTest::gmock
+    GTest::gtest
   TESTONLY
 )
 
@@ -136,8 +136,8 @@ absl_cc_test(
   DEPS
     absl::random_mocking_bit_gen
     absl::random_random
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -153,8 +153,8 @@ absl_cc_test(
     absl::random_bit_gen_ref
     absl::random_mocking_bit_gen
     absl::random_random
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_library(
@@ -245,8 +245,8 @@ absl_cc_test(
     absl::random_random
     absl::random_internal_sequence_urbg
     absl::random_internal_pcg_engine
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -268,8 +268,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::str_format
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -285,8 +285,8 @@ absl_cc_test(
     absl::random_distributions
     absl::random_random
     absl::random_internal_distribution_test_util
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -301,8 +301,8 @@ absl_cc_test(
     absl::random_distributions
     absl::random_random
     absl::raw_logging_internal
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -322,8 +322,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::str_format
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -343,8 +343,8 @@ absl_cc_test(
     absl::random_random
     absl::raw_logging_internal
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -367,8 +367,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::str_format
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -391,8 +391,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::str_format
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -414,8 +414,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::str_format
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -435,8 +435,8 @@ absl_cc_test(
     absl::random_random
     absl::raw_logging_internal
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -456,8 +456,8 @@ absl_cc_test(
     absl::random_internal_sequence_urbg
     absl::random_random
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -477,8 +477,8 @@ absl_cc_test(
     absl::random_random
     absl::raw_logging_internal
     absl::strings
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -492,7 +492,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_random
-    gtest_main
+    GTest::gtest_main
 )
 
 absl_cc_test(
@@ -508,8 +508,8 @@ absl_cc_test(
     absl::random_seed_sequences
     absl::random_internal_nonsecure_base
     absl::random_random
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -894,7 +894,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_traits
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -911,7 +911,7 @@ absl_cc_test(
     absl::bits
     absl::flags
     absl::random_internal_generate_real
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -926,7 +926,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_distribution_test_util
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -941,7 +941,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_fastmath
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -957,8 +957,8 @@ absl_cc_test(
   DEPS
     absl::random_internal_explicit_seed_seq
     absl::random_seed_sequences
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -973,8 +973,8 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_salted_seed_seq
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -990,7 +990,7 @@ absl_cc_test(
   DEPS
     absl::core_headers
     absl::random_internal_distribution_test_util
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1005,7 +1005,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_fast_uniform_bits
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1024,7 +1024,7 @@ absl_cc_test(
     absl::random_distributions
     absl::random_seed_sequences
     absl::strings
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1039,8 +1039,8 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_seed_material
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1057,7 +1057,7 @@ absl_cc_test(
     absl::random_internal_pool_urbg
     absl::span
     absl::type_traits
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1074,8 +1074,8 @@ absl_cc_test(
     absl::random_internal_explicit_seed_seq
     absl::random_internal_pcg_engine
     absl::time
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1094,8 +1094,8 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::time
-    gmock
-    gtest_main
+    GTest::gmock
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1111,7 +1111,7 @@ absl_cc_test(
   DEPS
     absl::random_internal_randen
     absl::type_traits
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1127,7 +1127,7 @@ absl_cc_test(
   DEPS
     absl::endian
     absl::random_internal_randen_slow
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1146,8 +1146,8 @@ absl_cc_test(
     absl::random_internal_randen_hwaes_impl
     absl::raw_logging_internal
     absl::str_format
-    gmock
-    gtest
+    GTest::gmock
+    GTest::gtest
 )
 
 # Internal-only target, do not depend on directly.
@@ -1178,7 +1178,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_uniform_helper
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1193,7 +1193,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_iostream_state_saver
-    gtest_main
+    GTest::gtest_main
 )
 
 # Internal-only target, do not depend on directly.
@@ -1210,5 +1210,5 @@ absl_cc_test(
     absl::random_internal_wide_multiply
     absl::bits
     absl::int128
-    gtest_main
+    GTest::gtest_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/random/beta_distribution_test.cc b/chromium/third_party/abseil-cpp/absl/random/beta_distribution_test.cc
index 44cdfdd0499..d980c969f7f 100644
--- a/chromium/third_party/abseil-cpp/absl/random/beta_distribution_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/beta_distribution_test.cc
@@ -15,6 +15,7 @@
 #include "absl/random/beta_distribution.h"
 
 #include <algorithm>
+#include <cfloat>
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
@@ -558,6 +559,14 @@ TEST(BetaDistributionTest, StabilityTest) {
 // dependencies of the distribution change, such as RandU64ToDouble, then this
 // is also likely to change.
 TEST(BetaDistributionTest, AlgorithmBounds) {
+#if (defined(__i386__) || defined(_M_IX86)) && FLT_EVAL_METHOD != 0
+  // We're using an x87-compatible FPU, and intermediate operations are
+  // performed with 80-bit floats. This produces slightly different results from
+  // what we expect below.
+  GTEST_SKIP()
+      << "Skipping the test because we detected x87 floating-point semantics";
+#endif
+
   {
     absl::random_internal::sequence_urbg urbg(
         {0x7fbe76c8b4395800ull, 0x8000000000000000ull});
diff --git a/chromium/third_party/abseil-cpp/absl/random/distributions_test.cc b/chromium/third_party/abseil-cpp/absl/random/distributions_test.cc
index 5866a07257e..d3a5dd75e57 100644
--- a/chromium/third_party/abseil-cpp/absl/random/distributions_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/distributions_test.cc
@@ -14,6 +14,7 @@
 
 #include "absl/random/distributions.h"
 
+#include <cfloat>
 #include <cmath>
 #include <cstdint>
 #include <random>
@@ -224,6 +225,15 @@ TEST_F(RandomDistributionsTest, UniformNoBounds) {
 TEST_F(RandomDistributionsTest, UniformNonsenseRanges) {
   // The ranges used in this test are undefined behavior.
   // The results are arbitrary and subject to future changes.
+
+#if (defined(__i386__) || defined(_M_IX86)) && FLT_EVAL_METHOD != 0
+  // We're using an x87-compatible FPU, and intermediate operations can be
+  // performed with 80-bit floats. This produces slightly different results from
+  // what we expect below.
+  GTEST_SKIP()
+      << "Skipping the test because we detected x87 floating-point semantics";
+#endif
+
   absl::InsecureBitGen gen;
 
   // <uint>
diff --git a/chromium/third_party/abseil-cpp/absl/random/exponential_distribution_test.cc b/chromium/third_party/abseil-cpp/absl/random/exponential_distribution_test.cc
index af11d61c156..81a5d17bac6 100644
--- a/chromium/third_party/abseil-cpp/absl/random/exponential_distribution_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/exponential_distribution_test.cc
@@ -15,6 +15,7 @@
 #include "absl/random/exponential_distribution.h"
 
 #include <algorithm>
+#include <cfloat>
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
@@ -384,6 +385,15 @@ TEST(ExponentialDistributionTest, StabilityTest) {
 TEST(ExponentialDistributionTest, AlgorithmBounds) {
   // Relies on absl::uniform_real_distribution, so some of these comments
   // reference that.
+
+#if (defined(__i386__) || defined(_M_IX86)) && FLT_EVAL_METHOD != 0
+  // We're using an x87-compatible FPU, and intermediate operations can be
+  // performed with 80-bit floats. This produces slightly different results from
+  // what we expect below.
+  GTEST_SKIP()
+      << "Skipping the test because we detected x87 floating-point semantics";
+#endif
+
   absl::exponential_distribution<double> dist;
 
   {
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.bazel b/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.bazel
index 90efe85a88b..8420b5c561f 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.bazel
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.bazel
@@ -82,6 +82,7 @@ cc_library(
     deps = [
         ":fast_uniform_bits",
         "//absl/base:core_headers",
+        "//absl/base:dynamic_annotations",
         "//absl/base:raw_logging_internal",
         "//absl/strings",
         "//absl/types:optional",
@@ -296,6 +297,8 @@ cc_library(
         ":platform",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/base:endian",
+        "//absl/numeric:int128",
     ],
 )
 
@@ -336,6 +339,7 @@ cc_library(
         ":platform",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/numeric:int128",
     ],
 )
 
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.gn b/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.gn
index 8dbe7092a1f..b148711b9c5 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/BUILD.gn
@@ -36,6 +36,7 @@ absl_source_set("seed_material") {
   deps = [
     ":fast_uniform_bits",
     "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/base:dynamic_annotations",
     "//third_party/abseil-cpp/absl/base:raw_logging_internal",
     "//third_party/abseil-cpp/absl/strings",
     "//third_party/abseil-cpp/absl/types:optional",
@@ -184,6 +185,8 @@ absl_source_set("randen_slow") {
     ":platform",
     "//third_party/abseil-cpp/absl/base:config",
     "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/base:endian",
+    "//third_party/abseil-cpp/absl/numeric:int128",
   ]
 }
 
@@ -209,6 +212,7 @@ absl_source_set("randen_hwaes_impl") {
     ":platform",
     "//third_party/abseil-cpp/absl/base:config",
     "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/numeric:int128",
   ]
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/generate_real.h b/chromium/third_party/abseil-cpp/absl/random/internal/generate_real.h
index 4f62873d5d8..d5fbb44c243 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/generate_real.h
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/generate_real.h
@@ -127,10 +127,8 @@ inline RealType GenerateRealFromBits(uint64_t bits, int exp_bias = 0) {
 
   // Construct the 32-bit or 64-bit IEEE 754 floating-point value from
   // the individual fields: sign, exp, mantissa(bits).
-  uint_type val =
-      (std::is_same<SignedTag, GeneratePositiveTag>::value ? 0u : sign) |
-      (static_cast<uint_type>(exp) << kExp) |
-      (static_cast<uint_type>(bits) & kMask);
+  uint_type val = sign | (static_cast<uint_type>(exp) << kExp) |
+                  (static_cast<uint_type>(bits) & kMask);
 
   // bit_cast to the output-type
   real_type result;
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/randen_hwaes.cc b/chromium/third_party/abseil-cpp/absl/random/internal/randen_hwaes.cc
index b5a3f90aee6..ab51e4a3ee4 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/randen_hwaes.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/randen_hwaes.cc
@@ -23,6 +23,7 @@
 #include <cstring>
 
 #include "absl/base/attributes.h"
+#include "absl/numeric/int128.h"
 #include "absl/random/internal/platform.h"
 #include "absl/random/internal/randen_traits.h"
 
@@ -120,11 +121,6 @@ namespace {
 
 using absl::random_internal::RandenTraits;
 
-// Randen operates on 128-bit vectors.
-struct alignas(16) u64x2 {
-  uint64_t data[2];
-};
-
 }  // namespace
 
 // TARGET_CRYPTO defines a crypto attribute for each architecture.
@@ -186,7 +182,7 @@ inline ABSL_TARGET_CRYPTO Vector128 AesRound(const Vector128& state,
 }
 
 // Enables native loads in the round loop by pre-swapping.
-inline ABSL_TARGET_CRYPTO void SwapEndian(u64x2* state) {
+inline ABSL_TARGET_CRYPTO void SwapEndian(absl::uint128* state) {
   for (uint32_t block = 0; block < RandenTraits::kFeistelBlocks; ++block) {
     Vector128Store(ReverseBytes(Vector128Load(state + block)), state + block);
   }
@@ -270,7 +266,7 @@ namespace {
 class Vector128 {
  public:
   // Convert from/to intrinsics.
-  inline explicit Vector128(const __m128i& Vector128) : data_(Vector128) {}
+  inline explicit Vector128(const __m128i& v) : data_(v) {}
 
   inline __m128i data() const { return data_; }
 
@@ -327,7 +323,7 @@ namespace {
 
 // Block shuffles applies a shuffle to the entire state between AES rounds.
 // Improved odd-even shuffle from "New criterion for diffusion property".
-inline ABSL_TARGET_CRYPTO void BlockShuffle(u64x2* state) {
+inline ABSL_TARGET_CRYPTO void BlockShuffle(absl::uint128* state) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Expecting 16 FeistelBlocks.");
 
@@ -374,8 +370,9 @@ inline ABSL_TARGET_CRYPTO void BlockShuffle(u64x2* state) {
 // per 16 bytes (vs. 10 for AES-CTR). Computing eight round functions in
 // parallel hides the 7-cycle AESNI latency on HSW. Note that the Feistel
 // XORs are 'free' (included in the second AES instruction).
-inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+inline ABSL_TARGET_CRYPTO const absl::uint128* FeistelRound(
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Expecting 16 FeistelBlocks.");
 
@@ -436,7 +433,8 @@ inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
 // 2^64 queries if the round function is a PRF. This is similar to the b=8 case
 // of Simpira v2, but more efficient than its generic construction for b=16.
 inline ABSL_TARGET_CRYPTO void Permute(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   // (Successfully unrolled; the first iteration jumps into the second half)
 #ifdef __clang__
 #pragma clang loop unroll_count(2)
@@ -473,10 +471,11 @@ void ABSL_TARGET_CRYPTO RandenHwAes::Absorb(const void* seed_void,
   static_assert(RandenTraits::kStateBytes / sizeof(Vector128) == 16,
                 "Unexpected Randen kStateBlocks");
 
-  auto* state =
-      reinterpret_cast<u64x2 * ABSL_RANDOM_INTERNAL_RESTRICT>(state_void);
+  auto* state = reinterpret_cast<absl::uint128 * ABSL_RANDOM_INTERNAL_RESTRICT>(
+      state_void);
   const auto* seed =
-      reinterpret_cast<const u64x2 * ABSL_RANDOM_INTERNAL_RESTRICT>(seed_void);
+      reinterpret_cast<const absl::uint128 * ABSL_RANDOM_INTERNAL_RESTRICT>(
+          seed_void);
 
   Vector128 b1 = Vector128Load(state + 1);
   b1 ^= Vector128Load(seed + 0);
@@ -545,8 +544,8 @@ void ABSL_TARGET_CRYPTO RandenHwAes::Generate(const void* keys_void,
   static_assert(RandenTraits::kCapacityBytes == sizeof(Vector128),
                 "Capacity mismatch");
 
-  auto* state = reinterpret_cast<u64x2*>(state_void);
-  const auto* keys = reinterpret_cast<const u64x2*>(keys_void);
+  auto* state = reinterpret_cast<absl::uint128*>(state_void);
+  const auto* keys = reinterpret_cast<const absl::uint128*>(keys_void);
 
   const Vector128 prev_inner = Vector128Load(state);
 
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/randen_slow.cc b/chromium/third_party/abseil-cpp/absl/random/internal/randen_slow.cc
index 4e5f3dc1c7b..d5c9347ba98 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/randen_slow.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/randen_slow.cc
@@ -19,6 +19,8 @@
 #include <cstring>
 
 #include "absl/base/attributes.h"
+#include "absl/base/internal/endian.h"
+#include "absl/numeric/int128.h"
 #include "absl/random/internal/platform.h"
 #include "absl/random/internal/randen_traits.h"
 
@@ -38,192 +40,193 @@
 namespace {
 
 // AES portions based on rijndael-alg-fst.c,
-// https://fastcrypto.org/front/misc/rijndael-alg-fst.c
+// https://fastcrypto.org/front/misc/rijndael-alg-fst.c, and modified for
+// platform-endianness.
 //
 // Implementation of
 // http://www.csrc.nist.gov/publications/fips/fips197/fips-197.pdf
 constexpr uint32_t te0[256] = {
-    0xc66363a5, 0xf87c7c84, 0xee777799, 0xf67b7b8d, 0xfff2f20d, 0xd66b6bbd,
-    0xde6f6fb1, 0x91c5c554, 0x60303050, 0x02010103, 0xce6767a9, 0x562b2b7d,
-    0xe7fefe19, 0xb5d7d762, 0x4dababe6, 0xec76769a, 0x8fcaca45, 0x1f82829d,
-    0x89c9c940, 0xfa7d7d87, 0xeffafa15, 0xb25959eb, 0x8e4747c9, 0xfbf0f00b,
-    0x41adadec, 0xb3d4d467, 0x5fa2a2fd, 0x45afafea, 0x239c9cbf, 0x53a4a4f7,
-    0xe4727296, 0x9bc0c05b, 0x75b7b7c2, 0xe1fdfd1c, 0x3d9393ae, 0x4c26266a,
-    0x6c36365a, 0x7e3f3f41, 0xf5f7f702, 0x83cccc4f, 0x6834345c, 0x51a5a5f4,
-    0xd1e5e534, 0xf9f1f108, 0xe2717193, 0xabd8d873, 0x62313153, 0x2a15153f,
-    0x0804040c, 0x95c7c752, 0x46232365, 0x9dc3c35e, 0x30181828, 0x379696a1,
-    0x0a05050f, 0x2f9a9ab5, 0x0e070709, 0x24121236, 0x1b80809b, 0xdfe2e23d,
-    0xcdebeb26, 0x4e272769, 0x7fb2b2cd, 0xea75759f, 0x1209091b, 0x1d83839e,
-    0x582c2c74, 0x341a1a2e, 0x361b1b2d, 0xdc6e6eb2, 0xb45a5aee, 0x5ba0a0fb,
-    0xa45252f6, 0x763b3b4d, 0xb7d6d661, 0x7db3b3ce, 0x5229297b, 0xdde3e33e,
-    0x5e2f2f71, 0x13848497, 0xa65353f5, 0xb9d1d168, 0x00000000, 0xc1eded2c,
-    0x40202060, 0xe3fcfc1f, 0x79b1b1c8, 0xb65b5bed, 0xd46a6abe, 0x8dcbcb46,
-    0x67bebed9, 0x7239394b, 0x944a4ade, 0x984c4cd4, 0xb05858e8, 0x85cfcf4a,
-    0xbbd0d06b, 0xc5efef2a, 0x4faaaae5, 0xedfbfb16, 0x864343c5, 0x9a4d4dd7,
-    0x66333355, 0x11858594, 0x8a4545cf, 0xe9f9f910, 0x04020206, 0xfe7f7f81,
-    0xa05050f0, 0x783c3c44, 0x259f9fba, 0x4ba8a8e3, 0xa25151f3, 0x5da3a3fe,
-    0x804040c0, 0x058f8f8a, 0x3f9292ad, 0x219d9dbc, 0x70383848, 0xf1f5f504,
-    0x63bcbcdf, 0x77b6b6c1, 0xafdada75, 0x42212163, 0x20101030, 0xe5ffff1a,
-    0xfdf3f30e, 0xbfd2d26d, 0x81cdcd4c, 0x180c0c14, 0x26131335, 0xc3ecec2f,
-    0xbe5f5fe1, 0x359797a2, 0x884444cc, 0x2e171739, 0x93c4c457, 0x55a7a7f2,
-    0xfc7e7e82, 0x7a3d3d47, 0xc86464ac, 0xba5d5de7, 0x3219192b, 0xe6737395,
-    0xc06060a0, 0x19818198, 0x9e4f4fd1, 0xa3dcdc7f, 0x44222266, 0x542a2a7e,
-    0x3b9090ab, 0x0b888883, 0x8c4646ca, 0xc7eeee29, 0x6bb8b8d3, 0x2814143c,
-    0xa7dede79, 0xbc5e5ee2, 0x160b0b1d, 0xaddbdb76, 0xdbe0e03b, 0x64323256,
-    0x743a3a4e, 0x140a0a1e, 0x924949db, 0x0c06060a, 0x4824246c, 0xb85c5ce4,
-    0x9fc2c25d, 0xbdd3d36e, 0x43acacef, 0xc46262a6, 0x399191a8, 0x319595a4,
-    0xd3e4e437, 0xf279798b, 0xd5e7e732, 0x8bc8c843, 0x6e373759, 0xda6d6db7,
-    0x018d8d8c, 0xb1d5d564, 0x9c4e4ed2, 0x49a9a9e0, 0xd86c6cb4, 0xac5656fa,
-    0xf3f4f407, 0xcfeaea25, 0xca6565af, 0xf47a7a8e, 0x47aeaee9, 0x10080818,
-    0x6fbabad5, 0xf0787888, 0x4a25256f, 0x5c2e2e72, 0x381c1c24, 0x57a6a6f1,
-    0x73b4b4c7, 0x97c6c651, 0xcbe8e823, 0xa1dddd7c, 0xe874749c, 0x3e1f1f21,
-    0x964b4bdd, 0x61bdbddc, 0x0d8b8b86, 0x0f8a8a85, 0xe0707090, 0x7c3e3e42,
-    0x71b5b5c4, 0xcc6666aa, 0x904848d8, 0x06030305, 0xf7f6f601, 0x1c0e0e12,
-    0xc26161a3, 0x6a35355f, 0xae5757f9, 0x69b9b9d0, 0x17868691, 0x99c1c158,
-    0x3a1d1d27, 0x279e9eb9, 0xd9e1e138, 0xebf8f813, 0x2b9898b3, 0x22111133,
-    0xd26969bb, 0xa9d9d970, 0x078e8e89, 0x339494a7, 0x2d9b9bb6, 0x3c1e1e22,
-    0x15878792, 0xc9e9e920, 0x87cece49, 0xaa5555ff, 0x50282878, 0xa5dfdf7a,
-    0x038c8c8f, 0x59a1a1f8, 0x09898980, 0x1a0d0d17, 0x65bfbfda, 0xd7e6e631,
-    0x844242c6, 0xd06868b8, 0x824141c3, 0x299999b0, 0x5a2d2d77, 0x1e0f0f11,
-    0x7bb0b0cb, 0xa85454fc, 0x6dbbbbd6, 0x2c16163a,
+    0xa56363c6, 0x847c7cf8, 0x997777ee, 0x8d7b7bf6, 0x0df2f2ff, 0xbd6b6bd6,
+    0xb16f6fde, 0x54c5c591, 0x50303060, 0x03010102, 0xa96767ce, 0x7d2b2b56,
+    0x19fefee7, 0x62d7d7b5, 0xe6abab4d, 0x9a7676ec, 0x45caca8f, 0x9d82821f,
+    0x40c9c989, 0x877d7dfa, 0x15fafaef, 0xeb5959b2, 0xc947478e, 0x0bf0f0fb,
+    0xecadad41, 0x67d4d4b3, 0xfda2a25f, 0xeaafaf45, 0xbf9c9c23, 0xf7a4a453,
+    0x967272e4, 0x5bc0c09b, 0xc2b7b775, 0x1cfdfde1, 0xae93933d, 0x6a26264c,
+    0x5a36366c, 0x413f3f7e, 0x02f7f7f5, 0x4fcccc83, 0x5c343468, 0xf4a5a551,
+    0x34e5e5d1, 0x08f1f1f9, 0x937171e2, 0x73d8d8ab, 0x53313162, 0x3f15152a,
+    0x0c040408, 0x52c7c795, 0x65232346, 0x5ec3c39d, 0x28181830, 0xa1969637,
+    0x0f05050a, 0xb59a9a2f, 0x0907070e, 0x36121224, 0x9b80801b, 0x3de2e2df,
+    0x26ebebcd, 0x6927274e, 0xcdb2b27f, 0x9f7575ea, 0x1b090912, 0x9e83831d,
+    0x742c2c58, 0x2e1a1a34, 0x2d1b1b36, 0xb26e6edc, 0xee5a5ab4, 0xfba0a05b,
+    0xf65252a4, 0x4d3b3b76, 0x61d6d6b7, 0xceb3b37d, 0x7b292952, 0x3ee3e3dd,
+    0x712f2f5e, 0x97848413, 0xf55353a6, 0x68d1d1b9, 0x00000000, 0x2cededc1,
+    0x60202040, 0x1ffcfce3, 0xc8b1b179, 0xed5b5bb6, 0xbe6a6ad4, 0x46cbcb8d,
+    0xd9bebe67, 0x4b393972, 0xde4a4a94, 0xd44c4c98, 0xe85858b0, 0x4acfcf85,
+    0x6bd0d0bb, 0x2aefefc5, 0xe5aaaa4f, 0x16fbfbed, 0xc5434386, 0xd74d4d9a,
+    0x55333366, 0x94858511, 0xcf45458a, 0x10f9f9e9, 0x06020204, 0x817f7ffe,
+    0xf05050a0, 0x443c3c78, 0xba9f9f25, 0xe3a8a84b, 0xf35151a2, 0xfea3a35d,
+    0xc0404080, 0x8a8f8f05, 0xad92923f, 0xbc9d9d21, 0x48383870, 0x04f5f5f1,
+    0xdfbcbc63, 0xc1b6b677, 0x75dadaaf, 0x63212142, 0x30101020, 0x1affffe5,
+    0x0ef3f3fd, 0x6dd2d2bf, 0x4ccdcd81, 0x140c0c18, 0x35131326, 0x2fececc3,
+    0xe15f5fbe, 0xa2979735, 0xcc444488, 0x3917172e, 0x57c4c493, 0xf2a7a755,
+    0x827e7efc, 0x473d3d7a, 0xac6464c8, 0xe75d5dba, 0x2b191932, 0x957373e6,
+    0xa06060c0, 0x98818119, 0xd14f4f9e, 0x7fdcdca3, 0x66222244, 0x7e2a2a54,
+    0xab90903b, 0x8388880b, 0xca46468c, 0x29eeeec7, 0xd3b8b86b, 0x3c141428,
+    0x79dedea7, 0xe25e5ebc, 0x1d0b0b16, 0x76dbdbad, 0x3be0e0db, 0x56323264,
+    0x4e3a3a74, 0x1e0a0a14, 0xdb494992, 0x0a06060c, 0x6c242448, 0xe45c5cb8,
+    0x5dc2c29f, 0x6ed3d3bd, 0xefacac43, 0xa66262c4, 0xa8919139, 0xa4959531,
+    0x37e4e4d3, 0x8b7979f2, 0x32e7e7d5, 0x43c8c88b, 0x5937376e, 0xb76d6dda,
+    0x8c8d8d01, 0x64d5d5b1, 0xd24e4e9c, 0xe0a9a949, 0xb46c6cd8, 0xfa5656ac,
+    0x07f4f4f3, 0x25eaeacf, 0xaf6565ca, 0x8e7a7af4, 0xe9aeae47, 0x18080810,
+    0xd5baba6f, 0x887878f0, 0x6f25254a, 0x722e2e5c, 0x241c1c38, 0xf1a6a657,
+    0xc7b4b473, 0x51c6c697, 0x23e8e8cb, 0x7cdddda1, 0x9c7474e8, 0x211f1f3e,
+    0xdd4b4b96, 0xdcbdbd61, 0x868b8b0d, 0x858a8a0f, 0x907070e0, 0x423e3e7c,
+    0xc4b5b571, 0xaa6666cc, 0xd8484890, 0x05030306, 0x01f6f6f7, 0x120e0e1c,
+    0xa36161c2, 0x5f35356a, 0xf95757ae, 0xd0b9b969, 0x91868617, 0x58c1c199,
+    0x271d1d3a, 0xb99e9e27, 0x38e1e1d9, 0x13f8f8eb, 0xb398982b, 0x33111122,
+    0xbb6969d2, 0x70d9d9a9, 0x898e8e07, 0xa7949433, 0xb69b9b2d, 0x221e1e3c,
+    0x92878715, 0x20e9e9c9, 0x49cece87, 0xff5555aa, 0x78282850, 0x7adfdfa5,
+    0x8f8c8c03, 0xf8a1a159, 0x80898909, 0x170d0d1a, 0xdabfbf65, 0x31e6e6d7,
+    0xc6424284, 0xb86868d0, 0xc3414182, 0xb0999929, 0x772d2d5a, 0x110f0f1e,
+    0xcbb0b07b, 0xfc5454a8, 0xd6bbbb6d, 0x3a16162c,
 };
 
 constexpr uint32_t te1[256] = {
-    0xa5c66363, 0x84f87c7c, 0x99ee7777, 0x8df67b7b, 0x0dfff2f2, 0xbdd66b6b,
-    0xb1de6f6f, 0x5491c5c5, 0x50603030, 0x03020101, 0xa9ce6767, 0x7d562b2b,
-    0x19e7fefe, 0x62b5d7d7, 0xe64dabab, 0x9aec7676, 0x458fcaca, 0x9d1f8282,
-    0x4089c9c9, 0x87fa7d7d, 0x15effafa, 0xebb25959, 0xc98e4747, 0x0bfbf0f0,
-    0xec41adad, 0x67b3d4d4, 0xfd5fa2a2, 0xea45afaf, 0xbf239c9c, 0xf753a4a4,
-    0x96e47272, 0x5b9bc0c0, 0xc275b7b7, 0x1ce1fdfd, 0xae3d9393, 0x6a4c2626,
-    0x5a6c3636, 0x417e3f3f, 0x02f5f7f7, 0x4f83cccc, 0x5c683434, 0xf451a5a5,
-    0x34d1e5e5, 0x08f9f1f1, 0x93e27171, 0x73abd8d8, 0x53623131, 0x3f2a1515,
-    0x0c080404, 0x5295c7c7, 0x65462323, 0x5e9dc3c3, 0x28301818, 0xa1379696,
-    0x0f0a0505, 0xb52f9a9a, 0x090e0707, 0x36241212, 0x9b1b8080, 0x3ddfe2e2,
-    0x26cdebeb, 0x694e2727, 0xcd7fb2b2, 0x9fea7575, 0x1b120909, 0x9e1d8383,
-    0x74582c2c, 0x2e341a1a, 0x2d361b1b, 0xb2dc6e6e, 0xeeb45a5a, 0xfb5ba0a0,
-    0xf6a45252, 0x4d763b3b, 0x61b7d6d6, 0xce7db3b3, 0x7b522929, 0x3edde3e3,
-    0x715e2f2f, 0x97138484, 0xf5a65353, 0x68b9d1d1, 0x00000000, 0x2cc1eded,
-    0x60402020, 0x1fe3fcfc, 0xc879b1b1, 0xedb65b5b, 0xbed46a6a, 0x468dcbcb,
-    0xd967bebe, 0x4b723939, 0xde944a4a, 0xd4984c4c, 0xe8b05858, 0x4a85cfcf,
-    0x6bbbd0d0, 0x2ac5efef, 0xe54faaaa, 0x16edfbfb, 0xc5864343, 0xd79a4d4d,
-    0x55663333, 0x94118585, 0xcf8a4545, 0x10e9f9f9, 0x06040202, 0x81fe7f7f,
-    0xf0a05050, 0x44783c3c, 0xba259f9f, 0xe34ba8a8, 0xf3a25151, 0xfe5da3a3,
-    0xc0804040, 0x8a058f8f, 0xad3f9292, 0xbc219d9d, 0x48703838, 0x04f1f5f5,
-    0xdf63bcbc, 0xc177b6b6, 0x75afdada, 0x63422121, 0x30201010, 0x1ae5ffff,
-    0x0efdf3f3, 0x6dbfd2d2, 0x4c81cdcd, 0x14180c0c, 0x35261313, 0x2fc3ecec,
-    0xe1be5f5f, 0xa2359797, 0xcc884444, 0x392e1717, 0x5793c4c4, 0xf255a7a7,
-    0x82fc7e7e, 0x477a3d3d, 0xacc86464, 0xe7ba5d5d, 0x2b321919, 0x95e67373,
-    0xa0c06060, 0x98198181, 0xd19e4f4f, 0x7fa3dcdc, 0x66442222, 0x7e542a2a,
-    0xab3b9090, 0x830b8888, 0xca8c4646, 0x29c7eeee, 0xd36bb8b8, 0x3c281414,
-    0x79a7dede, 0xe2bc5e5e, 0x1d160b0b, 0x76addbdb, 0x3bdbe0e0, 0x56643232,
-    0x4e743a3a, 0x1e140a0a, 0xdb924949, 0x0a0c0606, 0x6c482424, 0xe4b85c5c,
-    0x5d9fc2c2, 0x6ebdd3d3, 0xef43acac, 0xa6c46262, 0xa8399191, 0xa4319595,
-    0x37d3e4e4, 0x8bf27979, 0x32d5e7e7, 0x438bc8c8, 0x596e3737, 0xb7da6d6d,
-    0x8c018d8d, 0x64b1d5d5, 0xd29c4e4e, 0xe049a9a9, 0xb4d86c6c, 0xfaac5656,
-    0x07f3f4f4, 0x25cfeaea, 0xafca6565, 0x8ef47a7a, 0xe947aeae, 0x18100808,
-    0xd56fbaba, 0x88f07878, 0x6f4a2525, 0x725c2e2e, 0x24381c1c, 0xf157a6a6,
-    0xc773b4b4, 0x5197c6c6, 0x23cbe8e8, 0x7ca1dddd, 0x9ce87474, 0x213e1f1f,
-    0xdd964b4b, 0xdc61bdbd, 0x860d8b8b, 0x850f8a8a, 0x90e07070, 0x427c3e3e,
-    0xc471b5b5, 0xaacc6666, 0xd8904848, 0x05060303, 0x01f7f6f6, 0x121c0e0e,
-    0xa3c26161, 0x5f6a3535, 0xf9ae5757, 0xd069b9b9, 0x91178686, 0x5899c1c1,
-    0x273a1d1d, 0xb9279e9e, 0x38d9e1e1, 0x13ebf8f8, 0xb32b9898, 0x33221111,
-    0xbbd26969, 0x70a9d9d9, 0x89078e8e, 0xa7339494, 0xb62d9b9b, 0x223c1e1e,
-    0x92158787, 0x20c9e9e9, 0x4987cece, 0xffaa5555, 0x78502828, 0x7aa5dfdf,
-    0x8f038c8c, 0xf859a1a1, 0x80098989, 0x171a0d0d, 0xda65bfbf, 0x31d7e6e6,
-    0xc6844242, 0xb8d06868, 0xc3824141, 0xb0299999, 0x775a2d2d, 0x111e0f0f,
-    0xcb7bb0b0, 0xfca85454, 0xd66dbbbb, 0x3a2c1616,
+    0x6363c6a5, 0x7c7cf884, 0x7777ee99, 0x7b7bf68d, 0xf2f2ff0d, 0x6b6bd6bd,
+    0x6f6fdeb1, 0xc5c59154, 0x30306050, 0x01010203, 0x6767cea9, 0x2b2b567d,
+    0xfefee719, 0xd7d7b562, 0xabab4de6, 0x7676ec9a, 0xcaca8f45, 0x82821f9d,
+    0xc9c98940, 0x7d7dfa87, 0xfafaef15, 0x5959b2eb, 0x47478ec9, 0xf0f0fb0b,
+    0xadad41ec, 0xd4d4b367, 0xa2a25ffd, 0xafaf45ea, 0x9c9c23bf, 0xa4a453f7,
+    0x7272e496, 0xc0c09b5b, 0xb7b775c2, 0xfdfde11c, 0x93933dae, 0x26264c6a,
+    0x36366c5a, 0x3f3f7e41, 0xf7f7f502, 0xcccc834f, 0x3434685c, 0xa5a551f4,
+    0xe5e5d134, 0xf1f1f908, 0x7171e293, 0xd8d8ab73, 0x31316253, 0x15152a3f,
+    0x0404080c, 0xc7c79552, 0x23234665, 0xc3c39d5e, 0x18183028, 0x969637a1,
+    0x05050a0f, 0x9a9a2fb5, 0x07070e09, 0x12122436, 0x80801b9b, 0xe2e2df3d,
+    0xebebcd26, 0x27274e69, 0xb2b27fcd, 0x7575ea9f, 0x0909121b, 0x83831d9e,
+    0x2c2c5874, 0x1a1a342e, 0x1b1b362d, 0x6e6edcb2, 0x5a5ab4ee, 0xa0a05bfb,
+    0x5252a4f6, 0x3b3b764d, 0xd6d6b761, 0xb3b37dce, 0x2929527b, 0xe3e3dd3e,
+    0x2f2f5e71, 0x84841397, 0x5353a6f5, 0xd1d1b968, 0x00000000, 0xededc12c,
+    0x20204060, 0xfcfce31f, 0xb1b179c8, 0x5b5bb6ed, 0x6a6ad4be, 0xcbcb8d46,
+    0xbebe67d9, 0x3939724b, 0x4a4a94de, 0x4c4c98d4, 0x5858b0e8, 0xcfcf854a,
+    0xd0d0bb6b, 0xefefc52a, 0xaaaa4fe5, 0xfbfbed16, 0x434386c5, 0x4d4d9ad7,
+    0x33336655, 0x85851194, 0x45458acf, 0xf9f9e910, 0x02020406, 0x7f7ffe81,
+    0x5050a0f0, 0x3c3c7844, 0x9f9f25ba, 0xa8a84be3, 0x5151a2f3, 0xa3a35dfe,
+    0x404080c0, 0x8f8f058a, 0x92923fad, 0x9d9d21bc, 0x38387048, 0xf5f5f104,
+    0xbcbc63df, 0xb6b677c1, 0xdadaaf75, 0x21214263, 0x10102030, 0xffffe51a,
+    0xf3f3fd0e, 0xd2d2bf6d, 0xcdcd814c, 0x0c0c1814, 0x13132635, 0xececc32f,
+    0x5f5fbee1, 0x979735a2, 0x444488cc, 0x17172e39, 0xc4c49357, 0xa7a755f2,
+    0x7e7efc82, 0x3d3d7a47, 0x6464c8ac, 0x5d5dbae7, 0x1919322b, 0x7373e695,
+    0x6060c0a0, 0x81811998, 0x4f4f9ed1, 0xdcdca37f, 0x22224466, 0x2a2a547e,
+    0x90903bab, 0x88880b83, 0x46468cca, 0xeeeec729, 0xb8b86bd3, 0x1414283c,
+    0xdedea779, 0x5e5ebce2, 0x0b0b161d, 0xdbdbad76, 0xe0e0db3b, 0x32326456,
+    0x3a3a744e, 0x0a0a141e, 0x494992db, 0x06060c0a, 0x2424486c, 0x5c5cb8e4,
+    0xc2c29f5d, 0xd3d3bd6e, 0xacac43ef, 0x6262c4a6, 0x919139a8, 0x959531a4,
+    0xe4e4d337, 0x7979f28b, 0xe7e7d532, 0xc8c88b43, 0x37376e59, 0x6d6ddab7,
+    0x8d8d018c, 0xd5d5b164, 0x4e4e9cd2, 0xa9a949e0, 0x6c6cd8b4, 0x5656acfa,
+    0xf4f4f307, 0xeaeacf25, 0x6565caaf, 0x7a7af48e, 0xaeae47e9, 0x08081018,
+    0xbaba6fd5, 0x7878f088, 0x25254a6f, 0x2e2e5c72, 0x1c1c3824, 0xa6a657f1,
+    0xb4b473c7, 0xc6c69751, 0xe8e8cb23, 0xdddda17c, 0x7474e89c, 0x1f1f3e21,
+    0x4b4b96dd, 0xbdbd61dc, 0x8b8b0d86, 0x8a8a0f85, 0x7070e090, 0x3e3e7c42,
+    0xb5b571c4, 0x6666ccaa, 0x484890d8, 0x03030605, 0xf6f6f701, 0x0e0e1c12,
+    0x6161c2a3, 0x35356a5f, 0x5757aef9, 0xb9b969d0, 0x86861791, 0xc1c19958,
+    0x1d1d3a27, 0x9e9e27b9, 0xe1e1d938, 0xf8f8eb13, 0x98982bb3, 0x11112233,
+    0x6969d2bb, 0xd9d9a970, 0x8e8e0789, 0x949433a7, 0x9b9b2db6, 0x1e1e3c22,
+    0x87871592, 0xe9e9c920, 0xcece8749, 0x5555aaff, 0x28285078, 0xdfdfa57a,
+    0x8c8c038f, 0xa1a159f8, 0x89890980, 0x0d0d1a17, 0xbfbf65da, 0xe6e6d731,
+    0x424284c6, 0x6868d0b8, 0x414182c3, 0x999929b0, 0x2d2d5a77, 0x0f0f1e11,
+    0xb0b07bcb, 0x5454a8fc, 0xbbbb6dd6, 0x16162c3a,
 };
 
 constexpr uint32_t te2[256] = {
-    0x63a5c663, 0x7c84f87c, 0x7799ee77, 0x7b8df67b, 0xf20dfff2, 0x6bbdd66b,
-    0x6fb1de6f, 0xc55491c5, 0x30506030, 0x01030201, 0x67a9ce67, 0x2b7d562b,
-    0xfe19e7fe, 0xd762b5d7, 0xabe64dab, 0x769aec76, 0xca458fca, 0x829d1f82,
-    0xc94089c9, 0x7d87fa7d, 0xfa15effa, 0x59ebb259, 0x47c98e47, 0xf00bfbf0,
-    0xadec41ad, 0xd467b3d4, 0xa2fd5fa2, 0xafea45af, 0x9cbf239c, 0xa4f753a4,
-    0x7296e472, 0xc05b9bc0, 0xb7c275b7, 0xfd1ce1fd, 0x93ae3d93, 0x266a4c26,
-    0x365a6c36, 0x3f417e3f, 0xf702f5f7, 0xcc4f83cc, 0x345c6834, 0xa5f451a5,
-    0xe534d1e5, 0xf108f9f1, 0x7193e271, 0xd873abd8, 0x31536231, 0x153f2a15,
-    0x040c0804, 0xc75295c7, 0x23654623, 0xc35e9dc3, 0x18283018, 0x96a13796,
-    0x050f0a05, 0x9ab52f9a, 0x07090e07, 0x12362412, 0x809b1b80, 0xe23ddfe2,
-    0xeb26cdeb, 0x27694e27, 0xb2cd7fb2, 0x759fea75, 0x091b1209, 0x839e1d83,
-    0x2c74582c, 0x1a2e341a, 0x1b2d361b, 0x6eb2dc6e, 0x5aeeb45a, 0xa0fb5ba0,
-    0x52f6a452, 0x3b4d763b, 0xd661b7d6, 0xb3ce7db3, 0x297b5229, 0xe33edde3,
-    0x2f715e2f, 0x84971384, 0x53f5a653, 0xd168b9d1, 0x00000000, 0xed2cc1ed,
-    0x20604020, 0xfc1fe3fc, 0xb1c879b1, 0x5bedb65b, 0x6abed46a, 0xcb468dcb,
-    0xbed967be, 0x394b7239, 0x4ade944a, 0x4cd4984c, 0x58e8b058, 0xcf4a85cf,
-    0xd06bbbd0, 0xef2ac5ef, 0xaae54faa, 0xfb16edfb, 0x43c58643, 0x4dd79a4d,
-    0x33556633, 0x85941185, 0x45cf8a45, 0xf910e9f9, 0x02060402, 0x7f81fe7f,
-    0x50f0a050, 0x3c44783c, 0x9fba259f, 0xa8e34ba8, 0x51f3a251, 0xa3fe5da3,
-    0x40c08040, 0x8f8a058f, 0x92ad3f92, 0x9dbc219d, 0x38487038, 0xf504f1f5,
-    0xbcdf63bc, 0xb6c177b6, 0xda75afda, 0x21634221, 0x10302010, 0xff1ae5ff,
-    0xf30efdf3, 0xd26dbfd2, 0xcd4c81cd, 0x0c14180c, 0x13352613, 0xec2fc3ec,
-    0x5fe1be5f, 0x97a23597, 0x44cc8844, 0x17392e17, 0xc45793c4, 0xa7f255a7,
-    0x7e82fc7e, 0x3d477a3d, 0x64acc864, 0x5de7ba5d, 0x192b3219, 0x7395e673,
-    0x60a0c060, 0x81981981, 0x4fd19e4f, 0xdc7fa3dc, 0x22664422, 0x2a7e542a,
-    0x90ab3b90, 0x88830b88, 0x46ca8c46, 0xee29c7ee, 0xb8d36bb8, 0x143c2814,
-    0xde79a7de, 0x5ee2bc5e, 0x0b1d160b, 0xdb76addb, 0xe03bdbe0, 0x32566432,
-    0x3a4e743a, 0x0a1e140a, 0x49db9249, 0x060a0c06, 0x246c4824, 0x5ce4b85c,
-    0xc25d9fc2, 0xd36ebdd3, 0xacef43ac, 0x62a6c462, 0x91a83991, 0x95a43195,
-    0xe437d3e4, 0x798bf279, 0xe732d5e7, 0xc8438bc8, 0x37596e37, 0x6db7da6d,
-    0x8d8c018d, 0xd564b1d5, 0x4ed29c4e, 0xa9e049a9, 0x6cb4d86c, 0x56faac56,
-    0xf407f3f4, 0xea25cfea, 0x65afca65, 0x7a8ef47a, 0xaee947ae, 0x08181008,
-    0xbad56fba, 0x7888f078, 0x256f4a25, 0x2e725c2e, 0x1c24381c, 0xa6f157a6,
-    0xb4c773b4, 0xc65197c6, 0xe823cbe8, 0xdd7ca1dd, 0x749ce874, 0x1f213e1f,
-    0x4bdd964b, 0xbddc61bd, 0x8b860d8b, 0x8a850f8a, 0x7090e070, 0x3e427c3e,
-    0xb5c471b5, 0x66aacc66, 0x48d89048, 0x03050603, 0xf601f7f6, 0x0e121c0e,
-    0x61a3c261, 0x355f6a35, 0x57f9ae57, 0xb9d069b9, 0x86911786, 0xc15899c1,
-    0x1d273a1d, 0x9eb9279e, 0xe138d9e1, 0xf813ebf8, 0x98b32b98, 0x11332211,
-    0x69bbd269, 0xd970a9d9, 0x8e89078e, 0x94a73394, 0x9bb62d9b, 0x1e223c1e,
-    0x87921587, 0xe920c9e9, 0xce4987ce, 0x55ffaa55, 0x28785028, 0xdf7aa5df,
-    0x8c8f038c, 0xa1f859a1, 0x89800989, 0x0d171a0d, 0xbfda65bf, 0xe631d7e6,
-    0x42c68442, 0x68b8d068, 0x41c38241, 0x99b02999, 0x2d775a2d, 0x0f111e0f,
-    0xb0cb7bb0, 0x54fca854, 0xbbd66dbb, 0x163a2c16,
+    0x63c6a563, 0x7cf8847c, 0x77ee9977, 0x7bf68d7b, 0xf2ff0df2, 0x6bd6bd6b,
+    0x6fdeb16f, 0xc59154c5, 0x30605030, 0x01020301, 0x67cea967, 0x2b567d2b,
+    0xfee719fe, 0xd7b562d7, 0xab4de6ab, 0x76ec9a76, 0xca8f45ca, 0x821f9d82,
+    0xc98940c9, 0x7dfa877d, 0xfaef15fa, 0x59b2eb59, 0x478ec947, 0xf0fb0bf0,
+    0xad41ecad, 0xd4b367d4, 0xa25ffda2, 0xaf45eaaf, 0x9c23bf9c, 0xa453f7a4,
+    0x72e49672, 0xc09b5bc0, 0xb775c2b7, 0xfde11cfd, 0x933dae93, 0x264c6a26,
+    0x366c5a36, 0x3f7e413f, 0xf7f502f7, 0xcc834fcc, 0x34685c34, 0xa551f4a5,
+    0xe5d134e5, 0xf1f908f1, 0x71e29371, 0xd8ab73d8, 0x31625331, 0x152a3f15,
+    0x04080c04, 0xc79552c7, 0x23466523, 0xc39d5ec3, 0x18302818, 0x9637a196,
+    0x050a0f05, 0x9a2fb59a, 0x070e0907, 0x12243612, 0x801b9b80, 0xe2df3de2,
+    0xebcd26eb, 0x274e6927, 0xb27fcdb2, 0x75ea9f75, 0x09121b09, 0x831d9e83,
+    0x2c58742c, 0x1a342e1a, 0x1b362d1b, 0x6edcb26e, 0x5ab4ee5a, 0xa05bfba0,
+    0x52a4f652, 0x3b764d3b, 0xd6b761d6, 0xb37dceb3, 0x29527b29, 0xe3dd3ee3,
+    0x2f5e712f, 0x84139784, 0x53a6f553, 0xd1b968d1, 0x00000000, 0xedc12ced,
+    0x20406020, 0xfce31ffc, 0xb179c8b1, 0x5bb6ed5b, 0x6ad4be6a, 0xcb8d46cb,
+    0xbe67d9be, 0x39724b39, 0x4a94de4a, 0x4c98d44c, 0x58b0e858, 0xcf854acf,
+    0xd0bb6bd0, 0xefc52aef, 0xaa4fe5aa, 0xfbed16fb, 0x4386c543, 0x4d9ad74d,
+    0x33665533, 0x85119485, 0x458acf45, 0xf9e910f9, 0x02040602, 0x7ffe817f,
+    0x50a0f050, 0x3c78443c, 0x9f25ba9f, 0xa84be3a8, 0x51a2f351, 0xa35dfea3,
+    0x4080c040, 0x8f058a8f, 0x923fad92, 0x9d21bc9d, 0x38704838, 0xf5f104f5,
+    0xbc63dfbc, 0xb677c1b6, 0xdaaf75da, 0x21426321, 0x10203010, 0xffe51aff,
+    0xf3fd0ef3, 0xd2bf6dd2, 0xcd814ccd, 0x0c18140c, 0x13263513, 0xecc32fec,
+    0x5fbee15f, 0x9735a297, 0x4488cc44, 0x172e3917, 0xc49357c4, 0xa755f2a7,
+    0x7efc827e, 0x3d7a473d, 0x64c8ac64, 0x5dbae75d, 0x19322b19, 0x73e69573,
+    0x60c0a060, 0x81199881, 0x4f9ed14f, 0xdca37fdc, 0x22446622, 0x2a547e2a,
+    0x903bab90, 0x880b8388, 0x468cca46, 0xeec729ee, 0xb86bd3b8, 0x14283c14,
+    0xdea779de, 0x5ebce25e, 0x0b161d0b, 0xdbad76db, 0xe0db3be0, 0x32645632,
+    0x3a744e3a, 0x0a141e0a, 0x4992db49, 0x060c0a06, 0x24486c24, 0x5cb8e45c,
+    0xc29f5dc2, 0xd3bd6ed3, 0xac43efac, 0x62c4a662, 0x9139a891, 0x9531a495,
+    0xe4d337e4, 0x79f28b79, 0xe7d532e7, 0xc88b43c8, 0x376e5937, 0x6ddab76d,
+    0x8d018c8d, 0xd5b164d5, 0x4e9cd24e, 0xa949e0a9, 0x6cd8b46c, 0x56acfa56,
+    0xf4f307f4, 0xeacf25ea, 0x65caaf65, 0x7af48e7a, 0xae47e9ae, 0x08101808,
+    0xba6fd5ba, 0x78f08878, 0x254a6f25, 0x2e5c722e, 0x1c38241c, 0xa657f1a6,
+    0xb473c7b4, 0xc69751c6, 0xe8cb23e8, 0xdda17cdd, 0x74e89c74, 0x1f3e211f,
+    0x4b96dd4b, 0xbd61dcbd, 0x8b0d868b, 0x8a0f858a, 0x70e09070, 0x3e7c423e,
+    0xb571c4b5, 0x66ccaa66, 0x4890d848, 0x03060503, 0xf6f701f6, 0x0e1c120e,
+    0x61c2a361, 0x356a5f35, 0x57aef957, 0xb969d0b9, 0x86179186, 0xc19958c1,
+    0x1d3a271d, 0x9e27b99e, 0xe1d938e1, 0xf8eb13f8, 0x982bb398, 0x11223311,
+    0x69d2bb69, 0xd9a970d9, 0x8e07898e, 0x9433a794, 0x9b2db69b, 0x1e3c221e,
+    0x87159287, 0xe9c920e9, 0xce8749ce, 0x55aaff55, 0x28507828, 0xdfa57adf,
+    0x8c038f8c, 0xa159f8a1, 0x89098089, 0x0d1a170d, 0xbf65dabf, 0xe6d731e6,
+    0x4284c642, 0x68d0b868, 0x4182c341, 0x9929b099, 0x2d5a772d, 0x0f1e110f,
+    0xb07bcbb0, 0x54a8fc54, 0xbb6dd6bb, 0x162c3a16,
 };
 
 constexpr uint32_t te3[256] = {
-    0x6363a5c6, 0x7c7c84f8, 0x777799ee, 0x7b7b8df6, 0xf2f20dff, 0x6b6bbdd6,
-    0x6f6fb1de, 0xc5c55491, 0x30305060, 0x01010302, 0x6767a9ce, 0x2b2b7d56,
-    0xfefe19e7, 0xd7d762b5, 0xababe64d, 0x76769aec, 0xcaca458f, 0x82829d1f,
-    0xc9c94089, 0x7d7d87fa, 0xfafa15ef, 0x5959ebb2, 0x4747c98e, 0xf0f00bfb,
-    0xadadec41, 0xd4d467b3, 0xa2a2fd5f, 0xafafea45, 0x9c9cbf23, 0xa4a4f753,
-    0x727296e4, 0xc0c05b9b, 0xb7b7c275, 0xfdfd1ce1, 0x9393ae3d, 0x26266a4c,
-    0x36365a6c, 0x3f3f417e, 0xf7f702f5, 0xcccc4f83, 0x34345c68, 0xa5a5f451,
-    0xe5e534d1, 0xf1f108f9, 0x717193e2, 0xd8d873ab, 0x31315362, 0x15153f2a,
-    0x04040c08, 0xc7c75295, 0x23236546, 0xc3c35e9d, 0x18182830, 0x9696a137,
-    0x05050f0a, 0x9a9ab52f, 0x0707090e, 0x12123624, 0x80809b1b, 0xe2e23ddf,
-    0xebeb26cd, 0x2727694e, 0xb2b2cd7f, 0x75759fea, 0x09091b12, 0x83839e1d,
-    0x2c2c7458, 0x1a1a2e34, 0x1b1b2d36, 0x6e6eb2dc, 0x5a5aeeb4, 0xa0a0fb5b,
-    0x5252f6a4, 0x3b3b4d76, 0xd6d661b7, 0xb3b3ce7d, 0x29297b52, 0xe3e33edd,
-    0x2f2f715e, 0x84849713, 0x5353f5a6, 0xd1d168b9, 0x00000000, 0xeded2cc1,
-    0x20206040, 0xfcfc1fe3, 0xb1b1c879, 0x5b5bedb6, 0x6a6abed4, 0xcbcb468d,
-    0xbebed967, 0x39394b72, 0x4a4ade94, 0x4c4cd498, 0x5858e8b0, 0xcfcf4a85,
-    0xd0d06bbb, 0xefef2ac5, 0xaaaae54f, 0xfbfb16ed, 0x4343c586, 0x4d4dd79a,
-    0x33335566, 0x85859411, 0x4545cf8a, 0xf9f910e9, 0x02020604, 0x7f7f81fe,
-    0x5050f0a0, 0x3c3c4478, 0x9f9fba25, 0xa8a8e34b, 0x5151f3a2, 0xa3a3fe5d,
-    0x4040c080, 0x8f8f8a05, 0x9292ad3f, 0x9d9dbc21, 0x38384870, 0xf5f504f1,
-    0xbcbcdf63, 0xb6b6c177, 0xdada75af, 0x21216342, 0x10103020, 0xffff1ae5,
-    0xf3f30efd, 0xd2d26dbf, 0xcdcd4c81, 0x0c0c1418, 0x13133526, 0xecec2fc3,
-    0x5f5fe1be, 0x9797a235, 0x4444cc88, 0x1717392e, 0xc4c45793, 0xa7a7f255,
-    0x7e7e82fc, 0x3d3d477a, 0x6464acc8, 0x5d5de7ba, 0x19192b32, 0x737395e6,
-    0x6060a0c0, 0x81819819, 0x4f4fd19e, 0xdcdc7fa3, 0x22226644, 0x2a2a7e54,
-    0x9090ab3b, 0x8888830b, 0x4646ca8c, 0xeeee29c7, 0xb8b8d36b, 0x14143c28,
-    0xdede79a7, 0x5e5ee2bc, 0x0b0b1d16, 0xdbdb76ad, 0xe0e03bdb, 0x32325664,
-    0x3a3a4e74, 0x0a0a1e14, 0x4949db92, 0x06060a0c, 0x24246c48, 0x5c5ce4b8,
-    0xc2c25d9f, 0xd3d36ebd, 0xacacef43, 0x6262a6c4, 0x9191a839, 0x9595a431,
-    0xe4e437d3, 0x79798bf2, 0xe7e732d5, 0xc8c8438b, 0x3737596e, 0x6d6db7da,
-    0x8d8d8c01, 0xd5d564b1, 0x4e4ed29c, 0xa9a9e049, 0x6c6cb4d8, 0x5656faac,
-    0xf4f407f3, 0xeaea25cf, 0x6565afca, 0x7a7a8ef4, 0xaeaee947, 0x08081810,
-    0xbabad56f, 0x787888f0, 0x25256f4a, 0x2e2e725c, 0x1c1c2438, 0xa6a6f157,
-    0xb4b4c773, 0xc6c65197, 0xe8e823cb, 0xdddd7ca1, 0x74749ce8, 0x1f1f213e,
-    0x4b4bdd96, 0xbdbddc61, 0x8b8b860d, 0x8a8a850f, 0x707090e0, 0x3e3e427c,
-    0xb5b5c471, 0x6666aacc, 0x4848d890, 0x03030506, 0xf6f601f7, 0x0e0e121c,
-    0x6161a3c2, 0x35355f6a, 0x5757f9ae, 0xb9b9d069, 0x86869117, 0xc1c15899,
-    0x1d1d273a, 0x9e9eb927, 0xe1e138d9, 0xf8f813eb, 0x9898b32b, 0x11113322,
-    0x6969bbd2, 0xd9d970a9, 0x8e8e8907, 0x9494a733, 0x9b9bb62d, 0x1e1e223c,
-    0x87879215, 0xe9e920c9, 0xcece4987, 0x5555ffaa, 0x28287850, 0xdfdf7aa5,
-    0x8c8c8f03, 0xa1a1f859, 0x89898009, 0x0d0d171a, 0xbfbfda65, 0xe6e631d7,
-    0x4242c684, 0x6868b8d0, 0x4141c382, 0x9999b029, 0x2d2d775a, 0x0f0f111e,
-    0xb0b0cb7b, 0x5454fca8, 0xbbbbd66d, 0x16163a2c,
+    0xc6a56363, 0xf8847c7c, 0xee997777, 0xf68d7b7b, 0xff0df2f2, 0xd6bd6b6b,
+    0xdeb16f6f, 0x9154c5c5, 0x60503030, 0x02030101, 0xcea96767, 0x567d2b2b,
+    0xe719fefe, 0xb562d7d7, 0x4de6abab, 0xec9a7676, 0x8f45caca, 0x1f9d8282,
+    0x8940c9c9, 0xfa877d7d, 0xef15fafa, 0xb2eb5959, 0x8ec94747, 0xfb0bf0f0,
+    0x41ecadad, 0xb367d4d4, 0x5ffda2a2, 0x45eaafaf, 0x23bf9c9c, 0x53f7a4a4,
+    0xe4967272, 0x9b5bc0c0, 0x75c2b7b7, 0xe11cfdfd, 0x3dae9393, 0x4c6a2626,
+    0x6c5a3636, 0x7e413f3f, 0xf502f7f7, 0x834fcccc, 0x685c3434, 0x51f4a5a5,
+    0xd134e5e5, 0xf908f1f1, 0xe2937171, 0xab73d8d8, 0x62533131, 0x2a3f1515,
+    0x080c0404, 0x9552c7c7, 0x46652323, 0x9d5ec3c3, 0x30281818, 0x37a19696,
+    0x0a0f0505, 0x2fb59a9a, 0x0e090707, 0x24361212, 0x1b9b8080, 0xdf3de2e2,
+    0xcd26ebeb, 0x4e692727, 0x7fcdb2b2, 0xea9f7575, 0x121b0909, 0x1d9e8383,
+    0x58742c2c, 0x342e1a1a, 0x362d1b1b, 0xdcb26e6e, 0xb4ee5a5a, 0x5bfba0a0,
+    0xa4f65252, 0x764d3b3b, 0xb761d6d6, 0x7dceb3b3, 0x527b2929, 0xdd3ee3e3,
+    0x5e712f2f, 0x13978484, 0xa6f55353, 0xb968d1d1, 0x00000000, 0xc12ceded,
+    0x40602020, 0xe31ffcfc, 0x79c8b1b1, 0xb6ed5b5b, 0xd4be6a6a, 0x8d46cbcb,
+    0x67d9bebe, 0x724b3939, 0x94de4a4a, 0x98d44c4c, 0xb0e85858, 0x854acfcf,
+    0xbb6bd0d0, 0xc52aefef, 0x4fe5aaaa, 0xed16fbfb, 0x86c54343, 0x9ad74d4d,
+    0x66553333, 0x11948585, 0x8acf4545, 0xe910f9f9, 0x04060202, 0xfe817f7f,
+    0xa0f05050, 0x78443c3c, 0x25ba9f9f, 0x4be3a8a8, 0xa2f35151, 0x5dfea3a3,
+    0x80c04040, 0x058a8f8f, 0x3fad9292, 0x21bc9d9d, 0x70483838, 0xf104f5f5,
+    0x63dfbcbc, 0x77c1b6b6, 0xaf75dada, 0x42632121, 0x20301010, 0xe51affff,
+    0xfd0ef3f3, 0xbf6dd2d2, 0x814ccdcd, 0x18140c0c, 0x26351313, 0xc32fecec,
+    0xbee15f5f, 0x35a29797, 0x88cc4444, 0x2e391717, 0x9357c4c4, 0x55f2a7a7,
+    0xfc827e7e, 0x7a473d3d, 0xc8ac6464, 0xbae75d5d, 0x322b1919, 0xe6957373,
+    0xc0a06060, 0x19988181, 0x9ed14f4f, 0xa37fdcdc, 0x44662222, 0x547e2a2a,
+    0x3bab9090, 0x0b838888, 0x8cca4646, 0xc729eeee, 0x6bd3b8b8, 0x283c1414,
+    0xa779dede, 0xbce25e5e, 0x161d0b0b, 0xad76dbdb, 0xdb3be0e0, 0x64563232,
+    0x744e3a3a, 0x141e0a0a, 0x92db4949, 0x0c0a0606, 0x486c2424, 0xb8e45c5c,
+    0x9f5dc2c2, 0xbd6ed3d3, 0x43efacac, 0xc4a66262, 0x39a89191, 0x31a49595,
+    0xd337e4e4, 0xf28b7979, 0xd532e7e7, 0x8b43c8c8, 0x6e593737, 0xdab76d6d,
+    0x018c8d8d, 0xb164d5d5, 0x9cd24e4e, 0x49e0a9a9, 0xd8b46c6c, 0xacfa5656,
+    0xf307f4f4, 0xcf25eaea, 0xcaaf6565, 0xf48e7a7a, 0x47e9aeae, 0x10180808,
+    0x6fd5baba, 0xf0887878, 0x4a6f2525, 0x5c722e2e, 0x38241c1c, 0x57f1a6a6,
+    0x73c7b4b4, 0x9751c6c6, 0xcb23e8e8, 0xa17cdddd, 0xe89c7474, 0x3e211f1f,
+    0x96dd4b4b, 0x61dcbdbd, 0x0d868b8b, 0x0f858a8a, 0xe0907070, 0x7c423e3e,
+    0x71c4b5b5, 0xccaa6666, 0x90d84848, 0x06050303, 0xf701f6f6, 0x1c120e0e,
+    0xc2a36161, 0x6a5f3535, 0xaef95757, 0x69d0b9b9, 0x17918686, 0x9958c1c1,
+    0x3a271d1d, 0x27b99e9e, 0xd938e1e1, 0xeb13f8f8, 0x2bb39898, 0x22331111,
+    0xd2bb6969, 0xa970d9d9, 0x07898e8e, 0x33a79494, 0x2db69b9b, 0x3c221e1e,
+    0x15928787, 0xc920e9e9, 0x8749cece, 0xaaff5555, 0x50782828, 0xa57adfdf,
+    0x038f8c8c, 0x59f8a1a1, 0x09808989, 0x1a170d0d, 0x65dabfbf, 0xd731e6e6,
+    0x84c64242, 0xd0b86868, 0x82c34141, 0x29b09999, 0x5a772d2d, 0x1e110f0f,
+    0x7bcbb0b0, 0xa8fc5454, 0x6dd6bbbb, 0x2c3a1616,
 };
 
 // Software implementation of the Vector128 class, using uint32_t
@@ -235,45 +238,13 @@ struct alignas(16) Vector128 {
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE Vector128
 Vector128Load(const void* from) {
   Vector128 result;
-  const uint8_t* src = reinterpret_cast<const uint8_t*>(from);
-  result.s[0] = static_cast<uint32_t>(src[0]) << 24 |
-                static_cast<uint32_t>(src[1]) << 16 |
-                static_cast<uint32_t>(src[2]) << 8 |
-                static_cast<uint32_t>(src[3]);
-  result.s[1] = static_cast<uint32_t>(src[4]) << 24 |
-                static_cast<uint32_t>(src[5]) << 16 |
-                static_cast<uint32_t>(src[6]) << 8 |
-                static_cast<uint32_t>(src[7]);
-  result.s[2] = static_cast<uint32_t>(src[8]) << 24 |
-                static_cast<uint32_t>(src[9]) << 16 |
-                static_cast<uint32_t>(src[10]) << 8 |
-                static_cast<uint32_t>(src[11]);
-  result.s[3] = static_cast<uint32_t>(src[12]) << 24 |
-                static_cast<uint32_t>(src[13]) << 16 |
-                static_cast<uint32_t>(src[14]) << 8 |
-                static_cast<uint32_t>(src[15]);
+  std::memcpy(result.s, from, sizeof(Vector128));
   return result;
 }
 
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void Vector128Store(
     const Vector128& v, void* to) {
-  uint8_t* dst = reinterpret_cast<uint8_t*>(to);
-  dst[0] = static_cast<uint8_t>(v.s[0] >> 24);
-  dst[1] = static_cast<uint8_t>(v.s[0] >> 16);
-  dst[2] = static_cast<uint8_t>(v.s[0] >> 8);
-  dst[3] = static_cast<uint8_t>(v.s[0]);
-  dst[4] = static_cast<uint8_t>(v.s[1] >> 24);
-  dst[5] = static_cast<uint8_t>(v.s[1] >> 16);
-  dst[6] = static_cast<uint8_t>(v.s[1] >> 8);
-  dst[7] = static_cast<uint8_t>(v.s[1]);
-  dst[8] = static_cast<uint8_t>(v.s[2] >> 24);
-  dst[9] = static_cast<uint8_t>(v.s[2] >> 16);
-  dst[10] = static_cast<uint8_t>(v.s[2] >> 8);
-  dst[11] = static_cast<uint8_t>(v.s[2]);
-  dst[12] = static_cast<uint8_t>(v.s[3] >> 24);
-  dst[13] = static_cast<uint8_t>(v.s[3] >> 16);
-  dst[14] = static_cast<uint8_t>(v.s[3] >> 8);
-  dst[15] = static_cast<uint8_t>(v.s[3]);
+  std::memcpy(to, v.s, sizeof(Vector128));
 }
 
 // One round of AES. "round_key" is a public constant for breaking the
@@ -281,39 +252,57 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void Vector128Store(
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE Vector128
 AesRound(const Vector128& state, const Vector128& round_key) {
   Vector128 result;
+#ifdef ABSL_IS_LITTLE_ENDIAN
   result.s[0] = round_key.s[0] ^                  //
-                te0[uint8_t(state.s[0] >> 24)] ^  //
-                te1[uint8_t(state.s[1] >> 16)] ^  //
-                te2[uint8_t(state.s[2] >> 8)] ^   //
-                te3[uint8_t(state.s[3])];
+                te0[uint8_t(state.s[0])] ^        //
+                te1[uint8_t(state.s[1] >> 8)] ^   //
+                te2[uint8_t(state.s[2] >> 16)] ^  //
+                te3[uint8_t(state.s[3] >> 24)];
   result.s[1] = round_key.s[1] ^                  //
-                te0[uint8_t(state.s[1] >> 24)] ^  //
-                te1[uint8_t(state.s[2] >> 16)] ^  //
-                te2[uint8_t(state.s[3] >> 8)] ^   //
-                te3[uint8_t(state.s[0])];
+                te0[uint8_t(state.s[1])] ^        //
+                te1[uint8_t(state.s[2] >> 8)] ^   //
+                te2[uint8_t(state.s[3] >> 16)] ^  //
+                te3[uint8_t(state.s[0] >> 24)];
   result.s[2] = round_key.s[2] ^                  //
-                te0[uint8_t(state.s[2] >> 24)] ^  //
-                te1[uint8_t(state.s[3] >> 16)] ^  //
-                te2[uint8_t(state.s[0] >> 8)] ^   //
-                te3[uint8_t(state.s[1])];
+                te0[uint8_t(state.s[2])] ^        //
+                te1[uint8_t(state.s[3] >> 8)] ^   //
+                te2[uint8_t(state.s[0] >> 16)] ^  //
+                te3[uint8_t(state.s[1] >> 24)];
   result.s[3] = round_key.s[3] ^                  //
-                te0[uint8_t(state.s[3] >> 24)] ^  //
-                te1[uint8_t(state.s[0] >> 16)] ^  //
-                te2[uint8_t(state.s[1] >> 8)] ^   //
-                te3[uint8_t(state.s[2])];
+                te0[uint8_t(state.s[3])] ^        //
+                te1[uint8_t(state.s[0] >> 8)] ^   //
+                te2[uint8_t(state.s[1] >> 16)] ^  //
+                te3[uint8_t(state.s[2] >> 24)];
+#else
+  result.s[0] = round_key.s[0] ^                  //
+                te0[uint8_t(state.s[0])] ^        //
+                te1[uint8_t(state.s[3] >> 8)] ^   //
+                te2[uint8_t(state.s[2] >> 16)] ^  //
+                te3[uint8_t(state.s[1] >> 24)];
+  result.s[1] = round_key.s[1] ^                  //
+                te0[uint8_t(state.s[1])] ^        //
+                te1[uint8_t(state.s[0] >> 8)] ^   //
+                te2[uint8_t(state.s[3] >> 16)] ^  //
+                te3[uint8_t(state.s[2] >> 24)];
+  result.s[2] = round_key.s[2] ^                  //
+                te0[uint8_t(state.s[2])] ^        //
+                te1[uint8_t(state.s[1] >> 8)] ^   //
+                te2[uint8_t(state.s[0] >> 16)] ^  //
+                te3[uint8_t(state.s[3] >> 24)];
+  result.s[3] = round_key.s[3] ^                  //
+                te0[uint8_t(state.s[3])] ^        //
+                te1[uint8_t(state.s[2] >> 8)] ^   //
+                te2[uint8_t(state.s[1] >> 16)] ^  //
+                te3[uint8_t(state.s[0] >> 24)];
+#endif
   return result;
 }
 
 using ::absl::random_internal::RandenTraits;
 
-// Randen operates on 128-bit vectors.
-struct alignas(16) u64x2 {
-  uint64_t data[2];
-};
-
 // The improved Feistel block shuffle function for 16 blocks.
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
-    u64x2* state) {
+    absl::uint128* state) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Feistel block shuffle only works for 16 blocks.");
 
@@ -323,31 +312,31 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
   // The fully unrolled loop without the memcpy improves the speed by about
   // 30% over the equivalent:
 #if 0
-  u64x2 source[RandenTraits::kFeistelBlocks];
+  absl::uint128 source[RandenTraits::kFeistelBlocks];
   std::memcpy(source, state, sizeof(source));
   for (size_t i = 0; i < RandenTraits::kFeistelBlocks; i++) {
-    const u64x2 v0 = source[shuffle[i]];
+    const absl::uint128 v0 = source[shuffle[i]];
     state[i] = v0;
   }
   return;
 #endif
 
-  const u64x2 v0 = state[shuffle[0]];
-  const u64x2 v1 = state[shuffle[1]];
-  const u64x2 v2 = state[shuffle[2]];
-  const u64x2 v3 = state[shuffle[3]];
-  const u64x2 v4 = state[shuffle[4]];
-  const u64x2 v5 = state[shuffle[5]];
-  const u64x2 v6 = state[shuffle[6]];
-  const u64x2 v7 = state[shuffle[7]];
-  const u64x2 w0 = state[shuffle[8]];
-  const u64x2 w1 = state[shuffle[9]];
-  const u64x2 w2 = state[shuffle[10]];
-  const u64x2 w3 = state[shuffle[11]];
-  const u64x2 w4 = state[shuffle[12]];
-  const u64x2 w5 = state[shuffle[13]];
-  const u64x2 w6 = state[shuffle[14]];
-  const u64x2 w7 = state[shuffle[15]];
+  const absl::uint128 v0 = state[shuffle[0]];
+  const absl::uint128 v1 = state[shuffle[1]];
+  const absl::uint128 v2 = state[shuffle[2]];
+  const absl::uint128 v3 = state[shuffle[3]];
+  const absl::uint128 v4 = state[shuffle[4]];
+  const absl::uint128 v5 = state[shuffle[5]];
+  const absl::uint128 v6 = state[shuffle[6]];
+  const absl::uint128 v7 = state[shuffle[7]];
+  const absl::uint128 w0 = state[shuffle[8]];
+  const absl::uint128 w1 = state[shuffle[9]];
+  const absl::uint128 w2 = state[shuffle[10]];
+  const absl::uint128 w3 = state[shuffle[11]];
+  const absl::uint128 w4 = state[shuffle[12]];
+  const absl::uint128 w5 = state[shuffle[13]];
+  const absl::uint128 w6 = state[shuffle[14]];
+  const absl::uint128 w7 = state[shuffle[15]];
   state[0] = v0;
   state[1] = v1;
   state[2] = v2;
@@ -371,9 +360,9 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
 // per 16 bytes (vs. 10 for AES-CTR). Computing eight round functions in
 // parallel hides the 7-cycle AESNI latency on HSW. Note that the Feistel
 // XORs are 'free' (included in the second AES instruction).
-inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const u64x2* FeistelRound(
-    u64x2* ABSL_RANDOM_INTERNAL_RESTRICT state,
-    const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const absl::uint128*
+FeistelRound(absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT state,
+             const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   for (size_t branch = 0; branch < RandenTraits::kFeistelBlocks; branch += 4) {
     const Vector128 s0 = Vector128Load(state + branch);
     const Vector128 s1 = Vector128Load(state + branch + 1);
@@ -398,7 +387,8 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const u64x2* FeistelRound(
 // 2^64 queries if the round function is a PRF. This is similar to the b=8 case
 // of Simpira v2, but more efficient than its generic construction for b=16.
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void Permute(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   for (size_t round = 0; round < RandenTraits::kFeistelRounds; ++round) {
     keys = FeistelRound(state, keys);
     BlockShuffle(state);
@@ -414,7 +404,11 @@ namespace random_internal {
 const void* RandenSlow::GetKeys() {
   // Round keys for one AES per Feistel round and branch.
   // The canonical implementation uses first digits of Pi.
+#ifdef ABSL_IS_LITTLE_ENDIAN
   return kRandenRoundKeys;
+#else
+  return kRandenRoundKeysBE;
+#endif
 }
 
 void RandenSlow::Absorb(const void* seed_void, void* state_void) {
@@ -437,19 +431,18 @@ void RandenSlow::Absorb(const void* seed_void, void* state_void) {
 }
 
 void RandenSlow::Generate(const void* keys_void, void* state_void) {
-  static_assert(RandenTraits::kCapacityBytes == sizeof(u64x2),
+  static_assert(RandenTraits::kCapacityBytes == sizeof(absl::uint128),
                 "Capacity mismatch");
 
-  auto* state = reinterpret_cast<u64x2*>(state_void);
-  const auto* keys = reinterpret_cast<const u64x2*>(keys_void);
+  auto* state = reinterpret_cast<absl::uint128*>(state_void);
+  const auto* keys = reinterpret_cast<const absl::uint128*>(keys_void);
 
-  const u64x2 prev_inner = state[0];
+  const absl::uint128 prev_inner = state[0];
 
   Permute(state, keys);
 
   // Ensure backtracking resistance.
-  state[0].data[0] ^= prev_inner.data[0];
-  state[0].data[1] ^= prev_inner.data[1];
+  *state ^= prev_inner;
 }
 
 }  // namespace random_internal
diff --git a/chromium/third_party/abseil-cpp/absl/random/internal/seed_material.cc b/chromium/third_party/abseil-cpp/absl/random/internal/seed_material.cc
index 4d38a57419e..c03cad8502a 100644
--- a/chromium/third_party/abseil-cpp/absl/random/internal/seed_material.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/internal/seed_material.cc
@@ -28,6 +28,7 @@
 #include <cstdlib>
 #include <cstring>
 
+#include "absl/base/dynamic_annotations.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/escaping.h"
@@ -50,6 +51,18 @@
 
 #endif
 
+#if defined(__GLIBC__) && \
+    (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25))
+// glibc >= 2.25 has getentropy()
+#define ABSL_RANDOM_USE_GET_ENTROPY 1
+#endif
+
+#if defined(__EMSCRIPTEN__)
+#include <sys/random.h>
+// Emscripten has getentropy, but it resides in a different header.
+#define ABSL_RANDOM_USE_GET_ENTROPY 1
+#endif
+
 #if defined(ABSL_RANDOM_USE_BCRYPT)
 #include <bcrypt.h>
 
@@ -122,8 +135,32 @@ bool ReadSeedMaterialFromOSEntropyImpl(absl::Span<uint32_t> values) {
 
 #else
 
+#if defined(ABSL_RANDOM_USE_GET_ENTROPY)
+// On *nix, use getentropy() if supported. Note that libc may support
+// getentropy(), but the kernel may not, in which case this function will return
+// false.
+bool ReadSeedMaterialFromGetEntropy(absl::Span<uint32_t> values) {
+  auto buffer = reinterpret_cast<uint8_t*>(values.data());
+  size_t buffer_size = sizeof(uint32_t) * values.size();
+  while (buffer_size > 0) {
+    // getentropy() has a maximum permitted length of 256.
+    size_t to_read = std::min<size_t>(buffer_size, 256);
+    int result = getentropy(buffer, to_read);
+    if (result < 0) {
+      return false;
+    }
+    // https://github.com/google/sanitizers/issues/1173
+    // MemorySanitizer can't see through getentropy().
+    ABSL_ANNOTATE_MEMORY_IS_INITIALIZED(buffer, to_read);
+    buffer += to_read;
+    buffer_size -= to_read;
+  }
+  return true;
+}
+#endif  // defined(ABSL_RANDOM_GETENTROPY)
+
 // On *nix, read entropy from /dev/urandom.
-bool ReadSeedMaterialFromOSEntropyImpl(absl::Span<uint32_t> values) {
+bool ReadSeedMaterialFromDevURandom(absl::Span<uint32_t> values) {
   const char kEntropyFile[] = "/dev/urandom";
 
   auto buffer = reinterpret_cast<uint8_t*>(values.data());
@@ -150,6 +187,17 @@ bool ReadSeedMaterialFromOSEntropyImpl(absl::Span<uint32_t> values) {
   return success;
 }
 
+bool ReadSeedMaterialFromOSEntropyImpl(absl::Span<uint32_t> values) {
+#if defined(ABSL_RANDOM_USE_GET_ENTROPY)
+  if (ReadSeedMaterialFromGetEntropy(values)) {
+    return true;
+  }
+#endif
+  // Libc may support getentropy, but the kernel may not, so we still have
+  // to fallback to ReadSeedMaterialFromDevURandom().
+  return ReadSeedMaterialFromDevURandom(values);
+}
+
 #endif
 
 }  // namespace
diff --git a/chromium/third_party/abseil-cpp/absl/random/mocking_bit_gen_test.cc b/chromium/third_party/abseil-cpp/absl/random/mocking_bit_gen_test.cc
index f63b6e420e0..c713ceafd26 100644
--- a/chromium/third_party/abseil-cpp/absl/random/mocking_bit_gen_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/mocking_bit_gen_test.cc
@@ -15,6 +15,7 @@
 //
 #include "absl/random/mocking_bit_gen.h"
 
+#include <cmath>
 #include <numeric>
 #include <random>
 
@@ -328,8 +329,9 @@ TEST(BasicMocking, WillByDefaultWithArgs) {
 
   absl::MockingBitGen gen;
   ON_CALL(absl::MockPoisson<int>(), Call(gen, _))
-      .WillByDefault(
-          [](double lambda) { return static_cast<int>(lambda * 10); });
+      .WillByDefault([](double lambda) {
+        return static_cast<int>(std::rint(lambda * 10));
+      });
   EXPECT_EQ(absl::Poisson<int>(gen, 1.7), 17);
   EXPECT_EQ(absl::Poisson<int>(gen, 0.03), 0);
 }
diff --git a/chromium/third_party/abseil-cpp/absl/random/uniform_real_distribution_test.cc b/chromium/third_party/abseil-cpp/absl/random/uniform_real_distribution_test.cc
index 18bcd3bce88..035bd284d18 100644
--- a/chromium/third_party/abseil-cpp/absl/random/uniform_real_distribution_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/random/uniform_real_distribution_test.cc
@@ -14,6 +14,7 @@
 
 #include "absl/random/uniform_real_distribution.h"
 
+#include <cfloat>
 #include <cmath>
 #include <cstdint>
 #include <iterator>
@@ -70,6 +71,14 @@ using RealTypes =
 TYPED_TEST_SUITE(UniformRealDistributionTest, RealTypes);
 
 TYPED_TEST(UniformRealDistributionTest, ParamSerializeTest) {
+#if (defined(__i386__) || defined(_M_IX86)) && FLT_EVAL_METHOD != 0
+  // We're using an x87-compatible FPU, and intermediate operations are
+  // performed with 80-bit floats. This produces slightly different results from
+  // what we expect below.
+  GTEST_SKIP()
+      << "Skipping the test because we detected x87 floating-point semantics";
+#endif
+
   using param_type =
       typename absl::uniform_real_distribution<TypeParam>::param_type;
 
diff --git a/chromium/third_party/abseil-cpp/absl/status/BUILD.bazel b/chromium/third_party/abseil-cpp/absl/status/BUILD.bazel
index 189bd73d0e4..30df22ae83c 100644
--- a/chromium/third_party/abseil-cpp/absl/status/BUILD.bazel
+++ b/chromium/third_party/abseil-cpp/absl/status/BUILD.bazel
@@ -78,6 +78,7 @@ cc_library(
     copts = ABSL_DEFAULT_COPTS,
     deps = [
         ":status",
+        "//absl/base",
         "//absl/base:core_headers",
         "//absl/base:raw_logging_internal",
         "//absl/meta:type_traits",
@@ -96,6 +97,7 @@ cc_test(
         ":statusor",
         "//absl/base",
         "//absl/memory",
+        "//absl/strings",
         "//absl/types:any",
         "//absl/utility",
         "@com_google_googletest//:gtest_main",
diff --git a/chromium/third_party/abseil-cpp/absl/status/BUILD.gn b/chromium/third_party/abseil-cpp/absl/status/BUILD.gn
index 740fb195159..7aee518c2af 100644
--- a/chromium/third_party/abseil-cpp/absl/status/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/absl/status/BUILD.gn
@@ -39,6 +39,7 @@ absl_source_set("statusor") {
   ]
   deps = [
     ":status",
+    "//third_party/abseil-cpp/absl/base",
     "//third_party/abseil-cpp/absl/base:core_headers",
     "//third_party/abseil-cpp/absl/base:raw_logging_internal",
     "//third_party/abseil-cpp/absl/meta:type_traits",
@@ -48,3 +49,21 @@ absl_source_set("statusor") {
   ]
 }
 
+absl_source_set("statusor_test") {
+  testonly = true
+  sources = [
+    "statusor_test.cc",
+  ]
+  deps = [
+    ":status",
+    ":statusor",
+    "//third_party/abseil-cpp/absl/base",
+    "//third_party/abseil-cpp/absl/memory",
+    "//third_party/abseil-cpp/absl/strings",
+    "//third_party/abseil-cpp/absl/types:any",
+    "//third_party/abseil-cpp/absl/utility",
+    "//third_party/googletest:gmock",
+    "//third_party/googletest:gtest",
+  ]
+}
+
diff --git a/chromium/third_party/abseil-cpp/absl/status/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/status/CMakeLists.txt
index f0d798a3732..438985649ff 100644
--- a/chromium/third_party/abseil-cpp/absl/status/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/status/CMakeLists.txt
@@ -50,7 +50,7 @@ absl_cc_test(
   DEPS
     absl::status
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -64,6 +64,7 @@ absl_cc_library(
   COPTS
     ${ABSL_DEFAULT_COPTS}
   DEPS
+    absl::base
     absl::status
     absl::core_headers
     absl::raw_logging_internal
@@ -84,5 +85,5 @@ absl_cc_test(
   DEPS
     absl::status
     absl::statusor
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/status/status.cc b/chromium/third_party/abseil-cpp/absl/status/status.cc
index 5a5cd5c239e..53c198e19b3 100644
--- a/chromium/third_party/abseil-cpp/absl/status/status.cc
+++ b/chromium/third_party/abseil-cpp/absl/status/status.cc
@@ -308,7 +308,7 @@ std::string Status::ToStringSlow(StatusToStringMode mode) const {
 }
 
 std::ostream& operator<<(std::ostream& os, const Status& x) {
-  os << x.ToString();
+  os << x.ToString(StatusToStringMode::kWithEverything);
   return os;
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/status/status.h b/chromium/third_party/abseil-cpp/absl/status/status.h
index 2e05f46e875..c5fe0a70f61 100644
--- a/chromium/third_party/abseil-cpp/absl/status/status.h
+++ b/chromium/third_party/abseil-cpp/absl/status/status.h
@@ -80,7 +80,7 @@ ABSL_NAMESPACE_BEGIN
 // `kFailedPrecondition` if both codes apply. Similarly prefer `kNotFound` or
 // `kAlreadyExists` over `kFailedPrecondition`.
 //
-// Because these errors may travel RPC boundaries, these codes are tied to the
+// Because these errors may cross RPC boundaries, these codes are tied to the
 // `google.rpc.Code` definitions within
 // https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
 // The string value of these RPC codes is denoted within each enum below.
@@ -114,10 +114,10 @@ enum class StatusCode : int {
   // StatusCode::kInvalidArgument
   //
   // kInvalidArgument (gRPC code "INVALID_ARGUMENT") indicates the caller
-  // specified an invalid argument, such a malformed filename. Note that such
-  // errors should be narrowly limited to indicate to the invalid nature of the
-  // arguments themselves. Errors with validly formed arguments that may cause
-  // errors with the state of the receiving system should be denoted with
+  // specified an invalid argument, such as a malformed filename. Note that use
+  // of such errors should be narrowly limited to indicate the invalid nature of
+  // the arguments themselves. Errors with validly formed arguments that may
+  // cause errors with the state of the receiving system should be denoted with
   // `kFailedPrecondition` instead.
   kInvalidArgument = 3,
 
@@ -137,14 +137,15 @@ enum class StatusCode : int {
   //
   // `kNotFound` is useful if a request should be denied for an entire class of
   // users, such as during a gradual feature rollout or undocumented allow list.
-  // If, instead, a request should be denied for specific sets of users, such as
-  // through user-based access control, use `kPermissionDenied` instead.
+  // If a request should be denied for specific sets of users, such as through
+  // user-based access control, use `kPermissionDenied` instead.
   kNotFound = 5,
 
   // StatusCode::kAlreadyExists
   //
-  // kAlreadyExists (gRPC code "ALREADY_EXISTS") indicates the entity that a
-  // caller attempted to create (such as file or directory) is already present.
+  // kAlreadyExists (gRPC code "ALREADY_EXISTS") indicates that the entity a
+  // caller attempted to create (such as a file or directory) is already
+  // present.
   kAlreadyExists = 6,
 
   // StatusCode::kPermissionDenied
@@ -183,7 +184,7 @@ enum class StatusCode : int {
   //      level (such as when a client-specified test-and-set fails, indicating
   //      the client should restart a read-modify-write sequence).
   //  (c) Use `kFailedPrecondition` if the client should not retry until
-  //      the system state has been explicitly fixed. For example, if an "rmdir"
+  //      the system state has been explicitly fixed. For example, if a "rmdir"
   //      fails because the directory is non-empty, `kFailedPrecondition`
   //      should be returned since the client should not retry unless
   //      the files are deleted from the directory.
@@ -283,7 +284,7 @@ std::ostream& operator<<(std::ostream& os, StatusCode code);
 // absl::StatusToStringMode
 //
 // An `absl::StatusToStringMode` is an enumerated type indicating how
-// `absl::Status::ToString()` should construct the output string for an non-ok
+// `absl::Status::ToString()` should construct the output string for a non-ok
 // status.
 enum class StatusToStringMode : int {
   // ToString will not contain any extra data (such as payloads). It will only
diff --git a/chromium/third_party/abseil-cpp/absl/status/statusor.cc b/chromium/third_party/abseil-cpp/absl/status/statusor.cc
index b954b45e32c..96642b340fb 100644
--- a/chromium/third_party/abseil-cpp/absl/status/statusor.cc
+++ b/chromium/third_party/abseil-cpp/absl/status/statusor.cc
@@ -16,6 +16,7 @@
 #include <cstdlib>
 #include <utility>
 
+#include "absl/base/call_once.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
@@ -26,13 +27,44 @@ ABSL_NAMESPACE_BEGIN
 BadStatusOrAccess::BadStatusOrAccess(absl::Status status)
     : status_(std::move(status)) {}
 
-BadStatusOrAccess::~BadStatusOrAccess() = default;
+BadStatusOrAccess::BadStatusOrAccess(const BadStatusOrAccess& other)
+    : status_(other.status_) {}
+
+BadStatusOrAccess& BadStatusOrAccess::operator=(
+    const BadStatusOrAccess& other) {
+  // Ensure assignment is correct regardless of whether this->InitWhat() has
+  // already been called.
+  other.InitWhat();
+  status_ = other.status_;
+  what_ = other.what_;
+  return *this;
+}
+
+BadStatusOrAccess& BadStatusOrAccess::operator=(BadStatusOrAccess&& other) {
+  // Ensure assignment is correct regardless of whether this->InitWhat() has
+  // already been called.
+  other.InitWhat();
+  status_ = std::move(other.status_);
+  what_ = std::move(other.what_);
+  return *this;
+}
+
+BadStatusOrAccess::BadStatusOrAccess(BadStatusOrAccess&& other)
+    : status_(std::move(other.status_)) {}
+
 const char* BadStatusOrAccess::what() const noexcept {
-  return "Bad StatusOr access";
+  InitWhat();
+  return what_.c_str();
 }
 
 const absl::Status& BadStatusOrAccess::status() const { return status_; }
 
+void BadStatusOrAccess::InitWhat() const {
+  absl::call_once(init_what_, [this] {
+    what_ = absl::StrCat("Bad StatusOr access: ", status_.ToString());
+  });
+}
+
 namespace internal_statusor {
 
 void Helper::HandleInvalidStatusCtorArg(absl::Status* status) {
diff --git a/chromium/third_party/abseil-cpp/absl/status/statusor.h b/chromium/third_party/abseil-cpp/absl/status/statusor.h
index b7c55cc8acc..235a3433107 100644
--- a/chromium/third_party/abseil-cpp/absl/status/statusor.h
+++ b/chromium/third_party/abseil-cpp/absl/status/statusor.h
@@ -44,6 +44,7 @@
 #include <utility>
 
 #include "absl/base/attributes.h"
+#include "absl/base/call_once.h"
 #include "absl/meta/type_traits.h"
 #include "absl/status/internal/statusor_internal.h"
 #include "absl/status/status.h"
@@ -72,13 +73,18 @@ ABSL_NAMESPACE_BEGIN
 class BadStatusOrAccess : public std::exception {
  public:
   explicit BadStatusOrAccess(absl::Status status);
-  ~BadStatusOrAccess() override;
+  ~BadStatusOrAccess() override = default;
+
+  BadStatusOrAccess(const BadStatusOrAccess& other);
+  BadStatusOrAccess& operator=(const BadStatusOrAccess& other);
+  BadStatusOrAccess(BadStatusOrAccess&& other);
+  BadStatusOrAccess& operator=(BadStatusOrAccess&& other);
 
   // BadStatusOrAccess::what()
   //
   // Returns the associated explanatory string of the `absl::StatusOr<T>`
-  // object's error code. This function only returns the string literal "Bad
-  // StatusOr Access" for cases when evaluating general exceptions.
+  // object's error code. This function contains information about the failing
+  // status, but its exact formatting may change and should not be depended on.
   //
   // The pointer of this string is guaranteed to be valid until any non-const
   // function is invoked on the exception object.
@@ -91,7 +97,11 @@ class BadStatusOrAccess : public std::exception {
   const absl::Status& status() const;
 
  private:
+  void InitWhat() const;
+
   absl::Status status_;
+  mutable absl::once_flag init_what_;
+  mutable std::string what_;
 };
 
 // Returned StatusOr objects may not be ignored.
@@ -437,8 +447,7 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
                               T, U&&>>>>>::value,
           int> = 0>
   StatusOr(U&& u)  // NOLINT
-      : StatusOr(absl::in_place, std::forward<U>(u)) {
-  }
+      : StatusOr(absl::in_place, std::forward<U>(u)) {}
 
   template <
       typename U = T,
@@ -457,8 +466,7 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
               absl::negation<std::is_convertible<U&&, T>>>::value,
           int> = 0>
   explicit StatusOr(U&& u)  // NOLINT
-      : StatusOr(absl::in_place, std::forward<U>(u)) {
-  }
+      : StatusOr(absl::in_place, std::forward<U>(u)) {}
 
   // StatusOr<T>::ok()
   //
@@ -481,7 +489,7 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   // Returns a reference to the current `absl::Status` contained within the
   // `absl::StatusOr<T>`. If `absl::StatusOr<T>` contains a `T`, then this
   // function returns `absl::OkStatus()`.
-  const Status& status() const &;
+  const Status& status() const&;
   Status status() &&;
 
   // StatusOr<T>::value()
@@ -661,7 +669,9 @@ StatusOr<T>::StatusOr(absl::in_place_t, std::initializer_list<U> ilist,
     : Base(absl::in_place, ilist, std::forward<Args>(args)...) {}
 
 template <typename T>
-const Status& StatusOr<T>::status() const & { return this->status_; }
+const Status& StatusOr<T>::status() const& {
+  return this->status_;
+}
 template <typename T>
 Status StatusOr<T>::status() && {
   return ok() ? OkStatus() : std::move(this->status_);
diff --git a/chromium/third_party/abseil-cpp/absl/status/statusor_test.cc b/chromium/third_party/abseil-cpp/absl/status/statusor_test.cc
index c2e8fb7e359..7cae90e185f 100644
--- a/chromium/third_party/abseil-cpp/absl/status/statusor_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/status/statusor_test.cc
@@ -17,6 +17,7 @@
 #include <array>
 #include <initializer_list>
 #include <memory>
+#include <string>
 #include <type_traits>
 #include <utility>
 
@@ -25,6 +26,7 @@
 #include "absl/base/casts.h"
 #include "absl/memory/memory.h"
 #include "absl/status/status.h"
+#include "absl/strings/string_view.h"
 #include "absl/types/any.h"
 #include "absl/utility/utility.h"
 
@@ -34,6 +36,7 @@ using ::testing::AllOf;
 using ::testing::AnyWith;
 using ::testing::ElementsAre;
 using ::testing::Field;
+using ::testing::HasSubstr;
 using ::testing::Ne;
 using ::testing::Not;
 using ::testing::Pointee;
@@ -257,9 +260,9 @@ TEST(StatusOr, TestMoveOnlyInitializationFromTemporaryByValueOrDie) {
 
 TEST(StatusOr, TestValueOrDieOverloadForConstTemporary) {
   static_assert(
-      std::is_same<const int&&,
-                   decltype(
-                       std::declval<const absl::StatusOr<int>&&>().value())>(),
+      std::is_same<
+          const int&&,
+          decltype(std::declval<const absl::StatusOr<int>&&>().value())>(),
       "value() for const temporaries should return const T&&");
 }
 
@@ -303,20 +306,57 @@ TEST(StatusOr, StatusCtorForwards) {
   EXPECT_NE(status.message(), "Some error");
 }
 
+TEST(BadStatusOrAccessTest, CopyConstructionWhatOk) {
+  absl::Status error =
+      absl::InternalError("some arbitrary message too big for the sso buffer");
+  absl::BadStatusOrAccess e1{error};
+  absl::BadStatusOrAccess e2{e1};
+  EXPECT_THAT(e1.what(), HasSubstr(error.ToString()));
+  EXPECT_THAT(e2.what(), HasSubstr(error.ToString()));
+}
+
+TEST(BadStatusOrAccessTest, CopyAssignmentWhatOk) {
+  absl::Status error =
+      absl::InternalError("some arbitrary message too big for the sso buffer");
+  absl::BadStatusOrAccess e1{error};
+  absl::BadStatusOrAccess e2{absl::InternalError("other")};
+  e2 = e1;
+  EXPECT_THAT(e1.what(), HasSubstr(error.ToString()));
+  EXPECT_THAT(e2.what(), HasSubstr(error.ToString()));
+}
+
+TEST(BadStatusOrAccessTest, MoveConstructionWhatOk) {
+  absl::Status error =
+      absl::InternalError("some arbitrary message too big for the sso buffer");
+  absl::BadStatusOrAccess e1{error};
+  absl::BadStatusOrAccess e2{std::move(e1)};
+  EXPECT_THAT(e2.what(), HasSubstr(error.ToString()));
+}
+
+TEST(BadStatusOrAccessTest, MoveAssignmentWhatOk) {
+  absl::Status error =
+      absl::InternalError("some arbitrary message too big for the sso buffer");
+  absl::BadStatusOrAccess e1{error};
+  absl::BadStatusOrAccess e2{absl::InternalError("other")};
+  e2 = std::move(e1);
+  EXPECT_THAT(e2.what(), HasSubstr(error.ToString()));
+}
+
 // Define `EXPECT_DEATH_OR_THROW` to test the behavior of `StatusOr::value`,
 // which either throws `BadStatusOrAccess` or `LOG(FATAL)` based on whether
 // exceptions are enabled.
 #ifdef ABSL_HAVE_EXCEPTIONS
-#define EXPECT_DEATH_OR_THROW(statement, status_)    \
-  EXPECT_THROW(                                      \
-      {                                              \
-        try {                                        \
-          statement;                                 \
-        } catch (const absl::BadStatusOrAccess& e) { \
-          EXPECT_EQ(e.status(), status_);            \
-          throw;                                     \
-        }                                            \
-      },                                             \
+#define EXPECT_DEATH_OR_THROW(statement, status_)                  \
+  EXPECT_THROW(                                                    \
+      {                                                            \
+        try {                                                      \
+          statement;                                               \
+        } catch (const absl::BadStatusOrAccess& e) {               \
+          EXPECT_EQ(e.status(), status_);                          \
+          EXPECT_THAT(e.what(), HasSubstr(e.status().ToString())); \
+          throw;                                                   \
+        }                                                          \
+      },                                                           \
       absl::BadStatusOrAccess);
 #else  // ABSL_HAVE_EXCEPTIONS
 #define EXPECT_DEATH_OR_THROW(statement, status) \
@@ -412,8 +452,6 @@ TEST(StatusOr, TestStatusCtor) {
   EXPECT_EQ(thing.status().code(), absl::StatusCode::kCancelled);
 }
 
-
-
 TEST(StatusOr, TestValueCtor) {
   const int kI = 4;
   const absl::StatusOr<int> thing(kI);
@@ -1300,8 +1338,6 @@ TEST(StatusOr, TestPointerDefaultCtor) {
   EXPECT_EQ(thing.status().code(), absl::StatusCode::kUnknown);
 }
 
-
-
 TEST(StatusOr, TestPointerStatusCtor) {
   absl::StatusOr<int*> thing(absl::CancelledError());
   EXPECT_FALSE(thing.ok());
diff --git a/chromium/third_party/abseil-cpp/absl/strings/BUILD.bazel b/chromium/third_party/abseil-cpp/absl/strings/BUILD.bazel
index 1cb5b3e51cb..f9735b4bedb 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/BUILD.bazel
+++ b/chromium/third_party/abseil-cpp/absl/strings/BUILD.bazel
@@ -269,10 +269,18 @@ cc_library(
     name = "cord_internal",
     srcs = [
         "internal/cord_internal.cc",
+        "internal/cord_rep_btree.cc",
+        "internal/cord_rep_btree_navigator.cc",
+        "internal/cord_rep_btree_reader.cc",
+        "internal/cord_rep_consume.cc",
         "internal/cord_rep_ring.cc",
     ],
     hdrs = [
         "internal/cord_internal.h",
+        "internal/cord_rep_btree.h",
+        "internal/cord_rep_btree_navigator.h",
+        "internal/cord_rep_btree_reader.h",
+        "internal/cord_rep_consume.h",
         "internal/cord_rep_flat.h",
         "internal/cord_rep_ring.h",
         "internal/cord_rep_ring_reader.h",
@@ -292,7 +300,59 @@ cc_library(
         "//absl/container:compressed_tuple",
         "//absl/container:inlined_vector",
         "//absl/container:layout",
+        "//absl/functional:function_ref",
         "//absl/meta:type_traits",
+        "//absl/types:span",
+    ],
+)
+
+cc_test(
+    name = "cord_rep_btree_test",
+    size = "medium",
+    srcs = ["internal/cord_rep_btree_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":cord_internal",
+        ":cord_rep_test_util",
+        ":strings",
+        "//absl/base:config",
+        "//absl/base:raw_logging_internal",
+        "//absl/cleanup",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_test(
+    name = "cord_rep_btree_navigator_test",
+    size = "medium",
+    srcs = ["internal/cord_rep_btree_navigator_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":cord_internal",
+        ":cord_rep_test_util",
+        ":strings",
+        "//absl/base:config",
+        "//absl/base:raw_logging_internal",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_test(
+    name = "cord_rep_btree_reader_test",
+    size = "medium",
+    srcs = ["internal/cord_rep_btree_reader_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":cord",
+        ":cord_internal",
+        ":cord_rep_test_util",
+        ":strings",
+        "//absl/base:config",
+        "//absl/base:raw_logging_internal",
+        "@com_google_googletest//:gtest_main",
     ],
 )
 
@@ -575,6 +635,19 @@ cc_library(
 )
 
 cc_library(
+    name = "cord_rep_test_util",
+    testonly = 1,
+    hdrs = ["internal/cord_rep_test_util.h"],
+    copts = ABSL_DEFAULT_COPTS,
+    deps = [
+        ":cord_internal",
+        ":strings",
+        "//absl/base:config",
+        "//absl/base:raw_logging_internal",
+    ],
+)
+
+cc_library(
     name = "cordz_test_helpers",
     testonly = 1,
     hdrs = ["cordz_test_helpers.h"],
@@ -650,6 +723,22 @@ cc_test(
 )
 
 cc_test(
+    name = "cord_rep_consume_test",
+    size = "medium",
+    srcs = ["internal/cord_rep_consume_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":cord_internal",
+        ":strings",
+        "//absl/base:config",
+        "//absl/base:core_headers",
+        "//absl/debugging:leak_check",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_test(
     name = "cord_ring_test",
     size = "medium",
     srcs = ["cord_ring_test.cc"],
diff --git a/chromium/third_party/abseil-cpp/absl/strings/BUILD.gn b/chromium/third_party/abseil-cpp/absl/strings/BUILD.gn
index 03866af6131..ad9f925449e 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/BUILD.gn
+++ b/chromium/third_party/abseil-cpp/absl/strings/BUILD.gn
@@ -120,10 +120,18 @@ absl_source_set("str_format_internal") {
 absl_source_set("cord_internal") {
   sources = [
     "internal/cord_internal.cc",
+    "internal/cord_rep_btree.cc",
+    "internal/cord_rep_btree_navigator.cc",
+    "internal/cord_rep_btree_reader.cc",
+    "internal/cord_rep_consume.cc",
     "internal/cord_rep_ring.cc",
   ]
   public = [
     "internal/cord_internal.h",
+    "internal/cord_rep_btree.h",
+    "internal/cord_rep_btree_navigator.h",
+    "internal/cord_rep_btree_reader.h",
+    "internal/cord_rep_consume.h",
     "internal/cord_rep_flat.h",
     "internal/cord_rep_ring.h",
     "internal/cord_rep_ring_reader.h",
@@ -140,7 +148,39 @@ absl_source_set("cord_internal") {
     "//third_party/abseil-cpp/absl/container:compressed_tuple",
     "//third_party/abseil-cpp/absl/container:inlined_vector",
     "//third_party/abseil-cpp/absl/container:layout",
+    "//third_party/abseil-cpp/absl/functional:function_ref",
     "//third_party/abseil-cpp/absl/meta:type_traits",
+    "//third_party/abseil-cpp/absl/types:span",
+  ]
+}
+
+absl_source_set("cord_rep_btree_test") {
+  testonly = true
+  sources = ["internal/cord_rep_btree_test.cc"]
+  deps = [
+    ":cord_internal",
+    ":cord_rep_test_util",
+    ":strings",
+    "//third_party/abseil-cpp/absl/base:config",
+    "//third_party/abseil-cpp/absl/base:raw_logging_internal",
+    "//third_party/abseil-cpp/absl/cleanup",
+    "//third_party/googletest:gmock",
+    "//third_party/googletest:gtest",
+  ]
+}
+
+absl_source_set("cord_rep_btree_reader_test") {
+  testonly = true
+  sources = ["internal/cord_rep_btree_reader_test.cc"]
+  deps = [
+    ":cord",
+    ":cord_internal",
+    ":cord_rep_test_util",
+    ":strings",
+    "//third_party/abseil-cpp/absl/base:config",
+    "//third_party/abseil-cpp/absl/base:raw_logging_internal",
+    "//third_party/googletest:gmock",
+    "//third_party/googletest:gtest",
   ]
 }
 
@@ -382,6 +422,17 @@ absl_source_set("cord_test_helpers") {
   ]
 }
 
+absl_source_set("cord_rep_test_util") {
+  testonly = true
+  public = ["internal/cord_rep_test_util.h"]
+  deps = [
+    ":cord_internal",
+    ":strings",
+    "//third_party/abseil-cpp/absl/base:config",
+    "//third_party/abseil-cpp/absl/base:raw_logging_internal",
+  ]
+}
+
 absl_source_set("cordz_test_helpers") {
   testonly = true
   public = ["cordz_test_helpers.h"]
@@ -420,6 +471,20 @@ absl_source_set("cordz_test") {
   ]
 }
 
+absl_source_set("cord_rep_consume_test") {
+  testonly = true
+  sources = ["internal/cord_rep_consume_test.cc"]
+  deps = [
+    ":cord_internal",
+    ":strings",
+    "//third_party/abseil-cpp/absl/base:config",
+    "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/debugging:leak_check",
+    "//third_party/googletest:gmock",
+    "//third_party/googletest:gtest",
+  ]
+}
+
 absl_source_set("pow10_helper") {
   testonly = true
   sources = [ "internal/pow10_helper.cc" ]
@@ -467,3 +532,17 @@ absl_source_set("string_view_test") {
     "//third_party/googletest:gtest",
   ]
 }
+
+absl_source_set("cord_rep_btree_navigator_test") {
+  testonly = true
+  sources = [ "internal/cord_rep_btree_navigator_test.cc" ]
+  deps = [
+    ":cord_internal",
+    ":cord_rep_test_util",
+    ":strings",
+    "//third_party/abseil-cpp/absl/base:config",
+    "//third_party/abseil-cpp/absl/base:raw_logging_internal",
+    "//third_party/googletest:gmock",
+    "//third_party/googletest:gtest",
+  ]
+}
diff --git a/chromium/third_party/abseil-cpp/absl/strings/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/strings/CMakeLists.txt
index d3f1523cf03..8ad5f9c7f92 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/strings/CMakeLists.txt
@@ -101,7 +101,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::base
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -115,7 +115,7 @@ absl_cc_test(
     absl::strings
     absl::core_headers
     absl::fixed_array
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -128,7 +128,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -142,7 +142,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -156,7 +156,7 @@ absl_cc_test(
     absl::strings_internal
     absl::base
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -169,7 +169,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -184,7 +184,7 @@ absl_cc_test(
     absl::config
     absl::core_headers
     absl::dynamic_annotations
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -197,7 +197,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -209,7 +209,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -226,7 +226,7 @@ absl_cc_test(
     absl::btree
     absl::flat_hash_map
     absl::node_hash_map
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -238,7 +238,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::strings_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -253,7 +253,7 @@ absl_cc_test(
     absl::base
     absl::core_headers
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -268,7 +268,7 @@ absl_cc_test(
     absl::base
     absl::core_headers
     absl::memory
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -281,7 +281,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -301,7 +301,7 @@ absl_cc_test(
     absl::random_random
     absl::random_distributions
     absl::strings_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -314,7 +314,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::base
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -326,7 +326,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::strings_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -340,7 +340,7 @@ absl_cc_test(
     absl::strings
     absl::str_format
     absl::pow10_helper
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -355,7 +355,7 @@ absl_cc_test(
     absl::strings
     absl::config
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -370,7 +370,7 @@ absl_cc_test(
   DEPS
     absl::strings
     absl::config
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -428,7 +428,7 @@ absl_cc_test(
     absl::cord
     absl::strings
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -442,7 +442,7 @@ absl_cc_test(
     absl::str_format
     absl::str_format_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -455,7 +455,7 @@ absl_cc_test(
   DEPS
     absl::str_format
     absl::str_format_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -467,7 +467,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::str_format_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -479,7 +479,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::str_format
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -494,7 +494,7 @@ absl_cc_test(
     absl::str_format_internal
     absl::raw_logging_internal
     absl::int128
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -507,7 +507,7 @@ absl_cc_test(
   DEPS
     absl::str_format_internal
     absl::cord
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -520,7 +520,7 @@ absl_cc_test(
   DEPS
     absl::str_format_internal
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -547,7 +547,7 @@ absl_cc_test(
   DEPS
     absl::pow10_helper
     absl::str_format
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -555,11 +555,19 @@ absl_cc_library(
     cord_internal
   HDRS
     "internal/cord_internal.h"
+    "internal/cord_rep_btree.h"
+    "internal/cord_rep_btree_navigator.h"
+    "internal/cord_rep_btree_reader.h"
+    "internal/cord_rep_consume.h"
     "internal/cord_rep_flat.h"
     "internal/cord_rep_ring.h"
     "internal/cord_rep_ring_reader.h"
   SRCS
     "internal/cord_internal.cc"
+    "internal/cord_rep_btree.cc"
+    "internal/cord_rep_btree_navigator.cc"
+    "internal/cord_rep_btree_reader.cc"
+    "internal/cord_rep_consume.cc"
     "internal/cord_rep_ring.cc"
   COPTS
     ${ABSL_DEFAULT_COPTS}
@@ -600,7 +608,7 @@ absl_cc_test(
     absl::cordz_update_tracker
     absl::core_headers
     absl::synchronization
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -628,7 +636,7 @@ absl_cc_test(
     absl::config
     absl::cordz_functions
     absl::cordz_test_helpers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -675,7 +683,7 @@ absl_cc_test(
     absl::random_distributions
     absl::synchronization
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -722,7 +730,7 @@ absl_cc_test(
     absl::span
     absl::stacktrace
     absl::symbolize
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -742,7 +750,7 @@ absl_cc_test(
     absl::cordz_update_scope
     absl::cordz_update_tracker
     absl::thread_pool
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -780,7 +788,7 @@ absl_cc_test(
     absl::synchronization
     absl::thread_pool
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -813,7 +821,7 @@ absl_cc_test(
     absl::cordz_update_scope
     absl::cordz_update_tracker
     absl::core_headers
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -847,6 +855,21 @@ absl_cc_library(
 
 absl_cc_library(
   NAME
+    cord_rep_test_util
+  HDRS
+    "internal/cord_rep_test_util.h"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::config
+    absl::cord_internal
+    absl::raw_logging_internal
+    absl::strings
+  TESTONLY
+)
+
+absl_cc_library(
+  NAME
     cord_test_helpers
   HDRS
     "cord_test_helpers.h"
@@ -899,7 +922,80 @@ absl_cc_test(
     absl::endian
     absl::raw_logging_internal
     absl::fixed_array
-    gmock_main
+    GTest::gmock_main
+)
+
+absl_cc_test(
+  NAME
+    cord_rep_consume_test
+  SRCS
+    "internal/cord_rep_consume_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::base
+    absl::config
+    absl::cord_internal
+    absl::core_headers
+    absl::function_ref
+    absl::raw_logging_internal
+    absl::strings
+    GTest::gmock_main
+)
+
+absl_cc_test(
+  NAME
+    cord_rep_btree_test
+  SRCS
+    "internal/cord_rep_btree_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::base
+    absl::cleanup
+    absl::config
+    absl::cord_internal
+    absl::cord_rep_test_util
+    absl::core_headers
+    absl::raw_logging_internal
+    absl::strings
+    GTest::gmock_main
+)
+
+absl_cc_test(
+  NAME
+    cord_rep_btree_navigator_test
+  SRCS
+    "internal/cord_rep_btree_navigator_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::base
+    absl::config
+    absl::cord_internal
+    absl::cord_rep_test_util
+    absl::core_headers
+    absl::raw_logging_internal
+    absl::strings
+    GTest::gmock_main
+)
+
+absl_cc_test(
+  NAME
+    cord_rep_btree_reader_test
+  SRCS
+    "internal/cord_rep_btree_reader_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::base
+    absl::config
+    absl::cord_internal
+    absl::cord_rep_test_util
+    absl::core_headers
+    absl::raw_logging_internal
+    absl::strings
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -916,7 +1012,7 @@ absl_cc_test(
     absl::core_headers
     absl::raw_logging_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -931,7 +1027,7 @@ absl_cc_test(
     absl::cord_internal
     absl::core_headers
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -955,5 +1051,5 @@ absl_cc_test(
     absl::core_headers
     absl::raw_logging_internal
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/strings/cord.cc b/chromium/third_party/abseil-cpp/absl/strings/cord.cc
index f5aa6e47883..e9d72fa8f43 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/cord.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/cord.cc
@@ -36,8 +36,8 @@
 #include "absl/container/inlined_vector.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_flat.h"
-#include "absl/strings/internal/cord_rep_ring.h"
 #include "absl/strings/internal/cordz_statistics.h"
 #include "absl/strings/internal/cordz_update_scope.h"
 #include "absl/strings/internal/cordz_update_tracker.h"
@@ -51,22 +51,16 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 
 using ::absl::cord_internal::CordRep;
+using ::absl::cord_internal::CordRepBtree;
 using ::absl::cord_internal::CordRepConcat;
 using ::absl::cord_internal::CordRepExternal;
 using ::absl::cord_internal::CordRepFlat;
-using ::absl::cord_internal::CordRepRing;
 using ::absl::cord_internal::CordRepSubstring;
 using ::absl::cord_internal::CordzUpdateTracker;
 using ::absl::cord_internal::InlineData;
 using ::absl::cord_internal::kMaxFlatLength;
 using ::absl::cord_internal::kMinFlatLength;
 
-using ::absl::cord_internal::CONCAT;
-using ::absl::cord_internal::EXTERNAL;
-using ::absl::cord_internal::FLAT;
-using ::absl::cord_internal::RING;
-using ::absl::cord_internal::SUBSTRING;
-
 using ::absl::cord_internal::kInlinedVectorSize;
 using ::absl::cord_internal::kMaxBytesToCopy;
 
@@ -100,13 +94,13 @@ static constexpr uint64_t min_length[] = {
 
 static const int kMinLengthSize = ABSL_ARRAYSIZE(min_length);
 
-static inline bool cord_ring_enabled() {
-  return cord_internal::cord_ring_buffer_enabled.load(
+static inline bool btree_enabled() {
+  return cord_internal::cord_btree_enabled.load(
       std::memory_order_relaxed);
 }
 
 static inline bool IsRootBalanced(CordRep* node) {
-  if (node->tag != CONCAT) {
+  if (!node->IsConcat()) {
     return true;
   } else if (node->concat()->depth() <= 15) {
     return true;
@@ -143,7 +137,7 @@ static inline CordRep* VerifyTree(CordRep* node) {
 
 // Return the depth of a node
 static int Depth(const CordRep* rep) {
-  if (rep->tag == CONCAT) {
+  if (rep->IsConcat()) {
     return rep->concat()->depth();
   } else {
     return 0;
@@ -176,7 +170,7 @@ static CordRep* RawConcat(CordRep* left, CordRep* right) {
   }
 
   CordRepConcat* rep = new CordRepConcat();
-  rep->tag = CONCAT;
+  rep->tag = cord_internal::CONCAT;
   SetConcatChildren(rep, left, right);
 
   return rep;
@@ -218,27 +212,25 @@ static CordRepFlat* CreateFlat(const char* data, size_t length,
   return flat;
 }
 
-// Creates a new flat or ringbuffer out of the specified array.
+// Creates a new flat or Btree out of the specified array.
 // The returned node has a refcount of 1.
-static CordRep* RingNewTree(const char* data, size_t length,
-                            size_t alloc_hint) {
+static CordRep* NewBtree(const char* data, size_t length, size_t alloc_hint) {
   if (length <= kMaxFlatLength) {
     return CreateFlat(data, length, alloc_hint);
   }
   CordRepFlat* flat = CreateFlat(data, kMaxFlatLength, 0);
   data += kMaxFlatLength;
   length -= kMaxFlatLength;
-  size_t extra = (length - 1) / kMaxFlatLength + 1;
-  auto* root = CordRepRing::Create(flat, extra);
-  return CordRepRing::Append(root, {data, length}, alloc_hint);
+  auto* root = CordRepBtree::Create(flat);
+  return CordRepBtree::Append(root, {data, length}, alloc_hint);
 }
 
 // Create a new tree out of the specified array.
 // The returned node has a refcount of 1.
 static CordRep* NewTree(const char* data, size_t length, size_t alloc_hint) {
   if (length == 0) return nullptr;
-  if (cord_ring_enabled()) {
-    return RingNewTree(data, length, alloc_hint);
+  if (btree_enabled()) {
+    return NewBtree(data, length, alloc_hint);
   }
   absl::FixedArray<CordRep*> reps((length - 1) / kMaxFlatLength + 1);
   size_t n = 0;
@@ -275,7 +267,7 @@ static CordRep* NewSubstring(CordRep* child, size_t offset, size_t length) {
     CordRepSubstring* rep = new CordRepSubstring();
     assert((offset + length) <= child->length);
     rep->length = length;
-    rep->tag = SUBSTRING;
+    rep->tag = cord_internal::SUBSTRING;
     rep->start = offset;
     rep->child = child;
     return VerifyTree(rep);
@@ -346,10 +338,10 @@ inline void Cord::InlineRep::remove_prefix(size_t n) {
   reduce_size(n);
 }
 
-// Returns `rep` converted into a CordRepRing.
-// Directly returns `rep` if `rep` is already a CordRepRing.
-static CordRepRing* ForceRing(CordRep* rep, size_t extra) {
-  return (rep->tag == RING) ? rep->ring() : CordRepRing::Create(rep, extra);
+// Returns `rep` converted into a CordRepBtree.
+// Directly returns `rep` if `rep` is already a CordRepBtree.
+static CordRepBtree* ForceBtree(CordRep* rep) {
+  return rep->IsBtree() ? rep->btree() : CordRepBtree::Create(rep);
 }
 
 void Cord::InlineRep::AppendTreeToInlined(CordRep* tree,
@@ -357,8 +349,8 @@ void Cord::InlineRep::AppendTreeToInlined(CordRep* tree,
   assert(!is_tree());
   if (!data_.is_empty()) {
     CordRepFlat* flat = MakeFlatWithExtraCapacity(0);
-    if (cord_ring_enabled()) {
-      tree = CordRepRing::Append(CordRepRing::Create(flat, 1), tree);
+    if (btree_enabled()) {
+      tree = CordRepBtree::Append(CordRepBtree::Create(flat), tree);
     } else {
       tree = Concat(flat, tree);
     }
@@ -369,8 +361,8 @@ void Cord::InlineRep::AppendTreeToInlined(CordRep* tree,
 void Cord::InlineRep::AppendTreeToTree(CordRep* tree, MethodIdentifier method) {
   assert(is_tree());
   const CordzUpdateScope scope(data_.cordz_info(), method);
-  if (cord_ring_enabled()) {
-    tree = CordRepRing::Append(ForceRing(data_.as_tree(), 1), tree);
+  if (btree_enabled()) {
+    tree = CordRepBtree::Append(ForceBtree(data_.as_tree()), tree);
   } else {
     tree = Concat(data_.as_tree(), tree);
   }
@@ -391,8 +383,8 @@ void Cord::InlineRep::PrependTreeToInlined(CordRep* tree,
   assert(!is_tree());
   if (!data_.is_empty()) {
     CordRepFlat* flat = MakeFlatWithExtraCapacity(0);
-    if (cord_ring_enabled()) {
-      tree = CordRepRing::Prepend(CordRepRing::Create(flat, 1), tree);
+    if (btree_enabled()) {
+      tree = CordRepBtree::Prepend(CordRepBtree::Create(flat), tree);
     } else {
       tree = Concat(tree, flat);
     }
@@ -404,8 +396,8 @@ void Cord::InlineRep::PrependTreeToTree(CordRep* tree,
                                         MethodIdentifier method) {
   assert(is_tree());
   const CordzUpdateScope scope(data_.cordz_info(), method);
-  if (cord_ring_enabled()) {
-    tree = CordRepRing::Prepend(ForceRing(data_.as_tree(), 1), tree);
+  if (btree_enabled()) {
+    tree = CordRepBtree::Prepend(ForceBtree(data_.as_tree()), tree);
   } else {
     tree = Concat(tree, data_.as_tree());
   }
@@ -427,8 +419,8 @@ void Cord::InlineRep::PrependTree(CordRep* tree, MethodIdentifier method) {
 // written to region and the actual size increase will be written to size.
 static inline bool PrepareAppendRegion(CordRep* root, char** region,
                                        size_t* size, size_t max_length) {
-  if (root->tag == RING && root->refcount.IsOne()) {
-    Span<char> span = root->ring()->GetAppendBuffer(max_length);
+  if (root->IsBtree() && root->refcount.IsOne()) {
+    Span<char> span = root->btree()->GetAppendBuffer(max_length);
     if (!span.empty()) {
       *region = span.data();
       *size = span.size();
@@ -438,11 +430,11 @@ static inline bool PrepareAppendRegion(CordRep* root, char** region,
 
   // Search down the right-hand path for a non-full FLAT node.
   CordRep* dst = root;
-  while (dst->tag == CONCAT && dst->refcount.IsOne()) {
+  while (dst->IsConcat() && dst->refcount.IsOne()) {
     dst = dst->concat()->right;
   }
 
-  if (dst->tag < FLAT || !dst->refcount.IsOne()) {
+  if (!dst->IsFlat() || !dst->refcount.IsOne()) {
     *region = nullptr;
     *size = 0;
     return false;
@@ -500,22 +492,48 @@ void Cord::InlineRep::GetAppendRegion(char** region, size_t* size,
   *region = new_node->Data();
   *size = new_node->length;
 
-  if (cord_ring_enabled()) {
-    rep = CordRepRing::Append(ForceRing(rep, 1), new_node);
+  if (btree_enabled()) {
+    rep = CordRepBtree::Append(ForceBtree(rep), new_node);
   } else {
     rep = Concat(rep, new_node);
   }
   CommitTree(root, rep, scope, method);
 }
 
+// Computes the memory side of the provided edge which must be a valid data edge
+// for a btrtee, i.e., a FLAT, EXTERNAL or SUBSTRING of a FLAT or EXTERNAL node.
+static bool RepMemoryUsageDataEdge(const CordRep* rep,
+                                   size_t* total_mem_usage) {
+  size_t maybe_sub_size = 0;
+  if (ABSL_PREDICT_FALSE(rep->IsSubstring())) {
+    maybe_sub_size = sizeof(cord_internal::CordRepSubstring);
+    rep = rep->substring()->child;
+  }
+  if (rep->IsFlat()) {
+    *total_mem_usage += maybe_sub_size + rep->flat()->AllocatedSize();
+    return true;
+  }
+  if (rep->IsExternal()) {
+    // We don't know anything about the embedded / bound data, but we can safely
+    // assume it is 'at least' a word / pointer to data. In the future we may
+    // choose to use the 'data' byte as a tag to identify the types of some
+    // well-known externals, such as a std::string instance.
+    *total_mem_usage += maybe_sub_size +
+                        sizeof(cord_internal::CordRepExternalImpl<intptr_t>) +
+                        rep->length;
+    return true;
+  }
+  return false;
+}
+
 // If the rep is a leaf, this will increment the value at total_mem_usage and
 // will return true.
 static bool RepMemoryUsageLeaf(const CordRep* rep, size_t* total_mem_usage) {
-  if (rep->tag >= FLAT) {
+  if (rep->IsFlat()) {
     *total_mem_usage += rep->flat()->AllocatedSize();
     return true;
   }
-  if (rep->tag == EXTERNAL) {
+  if (rep->IsExternal()) {
     // We don't know anything about the embedded / bound data, but we can safely
     // assume it is 'at least' a word / pointer to data. In the future we may
     // choose to use the 'data' byte as a tag to identify the types of some
@@ -630,7 +648,7 @@ Cord& Cord::operator=(absl::string_view src) {
   }
   if (tree != nullptr) {
     CordzUpdateScope scope(contents_.cordz_info(), method);
-    if (tree->tag >= FLAT && tree->flat()->Capacity() >= length &&
+    if (tree->IsFlat() && tree->flat()->Capacity() >= length &&
         tree->refcount.IsOne()) {
       // Copy in place if the existing FLAT node is reusable.
       memmove(tree->flat()->Data(), data, length);
@@ -690,9 +708,11 @@ void Cord::InlineRep::AppendArray(absl::string_view src,
     return;
   }
 
-  if (cord_ring_enabled()) {
-    rep = ForceRing(rep, (src.size() - 1) / kMaxFlatLength + 1);
-    rep = CordRepRing::Append(rep->ring(), src);
+  if (btree_enabled()) {
+    // TODO(b/192061034): keep legacy 10% growth rate: consider other rates.
+    rep = ForceBtree(rep);
+    const size_t alloc_hint = (std::min)(kMaxFlatLength, rep->length / 10);
+    rep = CordRepBtree::Append(rep->btree(), src, alloc_hint);
   } else {
     // Use new block(s) for any remaining bytes that were not handled above.
     // Alloc extra memory only if the right child of the root of the new tree
@@ -747,7 +767,7 @@ inline void Cord::AppendImpl(C&& src) {
       contents_.AppendArray({src.contents_.data(), src_size}, method);
       return;
     }
-    if (src_tree->tag >= FLAT) {
+    if (src_tree->IsFlat()) {
       // src tree just has one flat node.
       contents_.AppendArray({src_tree->flat()->Data(), src_size}, method);
       return;
@@ -769,9 +789,13 @@ inline void Cord::AppendImpl(C&& src) {
   contents_.AppendTree(rep, CordzUpdateTracker::kAppendCord);
 }
 
-void Cord::Append(const Cord& src) { AppendImpl(src); }
+void Cord::Append(const Cord& src) {
+  AppendImpl(src);
+}
 
-void Cord::Append(Cord&& src) { AppendImpl(std::move(src)); }
+void Cord::Append(Cord&& src) {
+  AppendImpl(std::move(src));
+}
 
 template <typename T, Cord::EnableIfString<T>>
 void Cord::Append(T&& src) {
@@ -833,7 +857,7 @@ static CordRep* RemovePrefixFrom(CordRep* node, size_t n) {
   if (n == 0) return CordRep::Ref(node);
   absl::InlinedVector<CordRep*, kInlinedVectorSize> rhs_stack;
 
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     assert(n <= node->length);
     if (n < node->concat()->left->length) {
       // Push right to stack, descend left.
@@ -852,7 +876,7 @@ static CordRep* RemovePrefixFrom(CordRep* node, size_t n) {
   } else {
     size_t start = n;
     size_t len = node->length - n;
-    if (node->tag == SUBSTRING) {
+    if (node->IsSubstring()) {
       // Consider in-place update of node, similar to in RemoveSuffixFrom().
       start += node->substring()->start;
       node = node->substring()->child;
@@ -875,7 +899,7 @@ static CordRep* RemoveSuffixFrom(CordRep* node, size_t n) {
   absl::InlinedVector<CordRep*, kInlinedVectorSize> lhs_stack;
   bool inplace_ok = node->refcount.IsOne();
 
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     assert(n <= node->length);
     if (n < node->concat()->right->length) {
       // Push left to stack, descend right.
@@ -892,7 +916,7 @@ static CordRep* RemoveSuffixFrom(CordRep* node, size_t n) {
 
   if (n == 0) {
     CordRep::Ref(node);
-  } else if (inplace_ok && node->tag != EXTERNAL) {
+  } else if (inplace_ok && !node->IsExternal()) {
     // Consider making a new buffer if the current node capacity is much
     // larger than the new length.
     CordRep::Ref(node);
@@ -900,7 +924,7 @@ static CordRep* RemoveSuffixFrom(CordRep* node, size_t n) {
   } else {
     size_t start = 0;
     size_t len = node->length - n;
-    if (node->tag == SUBSTRING) {
+    if (node->IsSubstring()) {
       start = node->substring()->start;
       node = node->substring()->child;
     }
@@ -923,8 +947,10 @@ void Cord::RemovePrefix(size_t n) {
   } else {
     auto constexpr method = CordzUpdateTracker::kRemovePrefix;
     CordzUpdateScope scope(contents_.cordz_info(), method);
-    if (tree->tag == RING) {
-      tree = CordRepRing::RemovePrefix(tree->ring(), n);
+    if (tree->IsBtree()) {
+      CordRep* old = tree;
+      tree = tree->btree()->SubTree(n, tree->length - n);
+      CordRep::Unref(old);
     } else {
       CordRep* newrep = RemovePrefixFrom(tree, n);
       CordRep::Unref(tree);
@@ -944,8 +970,10 @@ void Cord::RemoveSuffix(size_t n) {
   } else {
     auto constexpr method = CordzUpdateTracker::kRemoveSuffix;
     CordzUpdateScope scope(contents_.cordz_info(), method);
-    if (tree->tag == RING) {
-      tree = CordRepRing::RemoveSuffix(tree->ring(), n);
+    if (tree->IsBtree()) {
+      CordRep* old = tree;
+      tree = tree->btree()->SubTree(0, tree->length - n);
+      CordRep::Unref(old);
     } else {
       CordRep* newrep = RemoveSuffixFrom(tree, n);
       CordRep::Unref(tree);
@@ -984,8 +1012,8 @@ static CordRep* NewSubRange(CordRep* node, size_t pos, size_t n) {
       results.push_back(Concat(left, right));
     } else if (pos == 0 && n == node->length) {
       results.push_back(CordRep::Ref(node));
-    } else if (node->tag != CONCAT) {
-      if (node->tag == SUBSTRING) {
+    } else if (!node->IsConcat()) {
+      if (node->IsSubstring()) {
         pos += node->substring()->start;
         node = node->substring()->child;
       }
@@ -1037,9 +1065,8 @@ Cord Cord::Subcord(size_t pos, size_t new_size) const {
     return sub_cord;
   }
 
-  if (tree->tag == RING) {
-    CordRepRing* ring = CordRep::Ref(tree)->ring();
-    tree = CordRepRing::SubRing(ring, pos, new_size);
+  if (tree->IsBtree()) {
+    tree = tree->btree()->SubTree(pos, new_size);
   } else {
     tree = NewSubRange(tree, pos, new_size);
   }
@@ -1063,7 +1090,7 @@ class CordForest {
       CordRep* node = pending.back();
       pending.pop_back();
       CheckNode(node);
-      if (ABSL_PREDICT_FALSE(node->tag != CONCAT)) {
+      if (ABSL_PREDICT_FALSE(!node->IsConcat())) {
         AddNode(node);
         continue;
       }
@@ -1157,7 +1184,7 @@ class CordForest {
 
   static void CheckNode(CordRep* node) {
     ABSL_INTERNAL_CHECK(node->length != 0u, "");
-    if (node->tag == CONCAT) {
+    if (node->IsConcat()) {
       ABSL_INTERNAL_CHECK(node->concat()->left != nullptr, "");
       ABSL_INTERNAL_CHECK(node->concat()->right != nullptr, "");
       ABSL_INTERNAL_CHECK(node->length == (node->concat()->left->length +
@@ -1177,7 +1204,7 @@ class CordForest {
 
 static CordRep* Rebalance(CordRep* node) {
   VerifyTree(node);
-  assert(node->tag == CONCAT);
+  assert(node->IsConcat());
 
   if (node->length == 0) {
     return nullptr;
@@ -1227,28 +1254,33 @@ bool ComputeCompareResult<bool>(int memcmp_res) {
 
 }  // namespace
 
-// Helper routine. Locates the first flat chunk of the Cord without
-// initializing the iterator.
+// Helper routine. Locates the first flat or external chunk of the Cord without
+// initializing the iterator, and returns a string_view referencing the data.
 inline absl::string_view Cord::InlineRep::FindFlatStartPiece() const {
   if (!is_tree()) {
     return absl::string_view(data_.as_chars(), data_.inline_size());
   }
 
   CordRep* node = tree();
-  if (node->tag >= FLAT) {
+  if (node->IsFlat()) {
     return absl::string_view(node->flat()->Data(), node->length);
   }
 
-  if (node->tag == EXTERNAL) {
+  if (node->IsExternal()) {
     return absl::string_view(node->external()->base, node->length);
   }
 
-  if (node->tag == RING) {
-    return node->ring()->entry_data(node->ring()->head());
+  if (node->IsBtree()) {
+    CordRepBtree* tree = node->btree();
+    int height = tree->height();
+    while (--height >= 0) {
+      tree = tree->Edge(CordRepBtree::kFront)->btree();
+    }
+    return tree->Data(tree->begin());
   }
 
   // Walk down the left branches until we hit a non-CONCAT node.
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     node = node->concat()->left;
   }
 
@@ -1257,16 +1289,16 @@ inline absl::string_view Cord::InlineRep::FindFlatStartPiece() const {
   size_t length = node->length;
   assert(length != 0);
 
-  if (node->tag == SUBSTRING) {
+  if (node->IsSubstring()) {
     offset = node->substring()->start;
     node = node->substring()->child;
   }
 
-  if (node->tag >= FLAT) {
+  if (node->IsFlat()) {
     return absl::string_view(node->flat()->Data() + offset, length);
   }
 
-  assert((node->tag == EXTERNAL) && "Expect FLAT or EXTERNAL node here");
+  assert(node->IsExternal() && "Expect FLAT or EXTERNAL node here");
 
   return absl::string_view(node->external()->base + offset, length);
 }
@@ -1460,7 +1492,7 @@ Cord::ChunkIterator& Cord::ChunkIterator::AdvanceStack() {
 
   // Walk down the left branches until we hit a non-CONCAT node. Save the
   // right children to the stack for subsequent traversal.
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     stack_of_right_children.push_back(node->concat()->right);
     node = node->concat()->left;
   }
@@ -1468,15 +1500,15 @@ Cord::ChunkIterator& Cord::ChunkIterator::AdvanceStack() {
   // Get the child node if we encounter a SUBSTRING.
   size_t offset = 0;
   size_t length = node->length;
-  if (node->tag == SUBSTRING) {
+  if (node->IsSubstring()) {
     offset = node->substring()->start;
     node = node->substring()->child;
   }
 
-  assert(node->tag == EXTERNAL || node->tag >= FLAT);
+  assert(node->IsExternal() || node->IsFlat());
   assert(length != 0);
   const char* data =
-      node->tag == EXTERNAL ? node->external()->base : node->flat()->Data();
+      node->IsExternal() ? node->external()->base : node->flat()->Data();
   current_chunk_ = absl::string_view(data + offset, length);
   current_leaf_ = node;
   return *this;
@@ -1506,22 +1538,21 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
     return subcord;
   }
 
-  if (ring_reader_) {
+  if (btree_reader_) {
     size_t chunk_size = current_chunk_.size();
     if (n <= chunk_size && n <= kMaxBytesToCopy) {
       subcord = Cord(current_chunk_.substr(0, n), method);
+      if (n < chunk_size) {
+        current_chunk_.remove_prefix(n);
+      } else {
+        current_chunk_ = btree_reader_.Next();
+      }
     } else {
-      auto* ring = CordRep::Ref(ring_reader_.ring())->ring();
-      size_t offset = ring_reader_.length() - bytes_remaining_;
-      CordRep* rep = CordRepRing::SubRing(ring, offset, n);
+      CordRep* rep;
+      current_chunk_ = btree_reader_.Read(n, chunk_size, rep);
       subcord.contents_.EmplaceTree(rep, method);
     }
-    if (n < chunk_size) {
-      bytes_remaining_ -= n;
-      current_chunk_.remove_prefix(n);
-    } else {
-      AdvanceBytesRing(n);
-    }
+    bytes_remaining_ -= n;
     return subcord;
   }
 
@@ -1530,8 +1561,8 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
     // Range to read is a proper subrange of the current chunk.
     assert(current_leaf_ != nullptr);
     CordRep* subnode = CordRep::Ref(current_leaf_);
-    const char* data = subnode->tag == EXTERNAL ? subnode->external()->base
-                                                : subnode->flat()->Data();
+    const char* data = subnode->IsExternal() ? subnode->external()->base
+                                             : subnode->flat()->Data();
     subnode = NewSubstring(subnode, current_chunk_.data() - data, n);
     subcord.contents_.EmplaceTree(VerifyTree(subnode), method);
     RemoveChunkPrefix(n);
@@ -1543,8 +1574,8 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
   assert(current_leaf_ != nullptr);
   CordRep* subnode = CordRep::Ref(current_leaf_);
   if (current_chunk_.size() < subnode->length) {
-    const char* data = subnode->tag == EXTERNAL ? subnode->external()->base
-                                                : subnode->flat()->Data();
+    const char* data = subnode->IsExternal() ? subnode->external()->base
+                                             : subnode->flat()->Data();
     subnode = NewSubstring(subnode, current_chunk_.data() - data,
                            current_chunk_.size());
   }
@@ -1582,7 +1613,7 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
 
   // Walk down the appropriate branches until we hit a non-CONCAT node. Save the
   // right children to the stack for subsequent traversal.
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     if (node->concat()->left->length > n) {
       // Push right, descend left.
       stack_of_right_children.push_back(node->concat()->right);
@@ -1599,20 +1630,20 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
   // Get the child node if we encounter a SUBSTRING.
   size_t offset = 0;
   size_t length = node->length;
-  if (node->tag == SUBSTRING) {
+  if (node->IsSubstring()) {
     offset = node->substring()->start;
     node = node->substring()->child;
   }
 
   // Range to read ends with a proper (possibly empty) subrange of the current
   // chunk.
-  assert(node->tag == EXTERNAL || node->tag >= FLAT);
+  assert(node->IsExternal() || node->IsFlat());
   assert(length > n);
   if (n > 0) {
     subnode = Concat(subnode, NewSubstring(CordRep::Ref(node), offset, n));
   }
   const char* data =
-      node->tag == EXTERNAL ? node->external()->base : node->flat()->Data();
+      node->IsExternal() ? node->external()->base : node->flat()->Data();
   current_chunk_ = absl::string_view(data + offset + n, length - n);
   current_leaf_ = node;
   bytes_remaining_ -= n;
@@ -1655,7 +1686,7 @@ void Cord::ChunkIterator::AdvanceBytesSlowPath(size_t n) {
 
   // Walk down the appropriate branches until we hit a non-CONCAT node. Save the
   // right children to the stack for subsequent traversal.
-  while (node->tag == CONCAT) {
+  while (node->IsConcat()) {
     if (node->concat()->left->length > n) {
       // Push right, descend left.
       stack_of_right_children.push_back(node->concat()->right);
@@ -1671,15 +1702,15 @@ void Cord::ChunkIterator::AdvanceBytesSlowPath(size_t n) {
   // Get the child node if we encounter a SUBSTRING.
   size_t offset = 0;
   size_t length = node->length;
-  if (node->tag == SUBSTRING) {
+  if (node->IsSubstring()) {
     offset = node->substring()->start;
     node = node->substring()->child;
   }
 
-  assert(node->tag == EXTERNAL || node->tag >= FLAT);
+  assert(node->IsExternal() || node->IsFlat());
   assert(length > n);
   const char* data =
-      node->tag == EXTERNAL ? node->external()->base : node->flat()->Data();
+      node->IsExternal() ? node->external()->base : node->flat()->Data();
   current_chunk_ = absl::string_view(data + offset + n, length - n);
   current_leaf_ = node;
   bytes_remaining_ -= n;
@@ -1695,15 +1726,15 @@ char Cord::operator[](size_t i) const {
   while (true) {
     assert(rep != nullptr);
     assert(offset < rep->length);
-    if (rep->tag >= FLAT) {
+    if (rep->IsFlat()) {
       // Get the "i"th character directly from the flat array.
       return rep->flat()->Data()[offset];
-    } else if (rep->tag == RING) {
-      return rep->ring()->GetCharacter(offset);
-    } else if (rep->tag == EXTERNAL) {
+    } else if (rep->IsBtree()) {
+      return rep->btree()->GetCharacter(offset);
+    } else if (rep->IsExternal()) {
       // Get the "i"th character from the external array.
       return rep->external()->base[offset];
-    } else if (rep->tag == CONCAT) {
+    } else if (rep->IsConcat()) {
       // Recursively branch to the side of the concatenation that the "i"th
       // character is on.
       size_t left_length = rep->concat()->left->length;
@@ -1715,7 +1746,7 @@ char Cord::operator[](size_t i) const {
       }
     } else {
       // This must be a substring a node, so bypass it to get to the child.
-      assert(rep->tag == SUBSTRING);
+      assert(rep->IsSubstring());
       offset += rep->substring()->start;
       rep = rep->substring()->child;
     }
@@ -1752,27 +1783,27 @@ absl::string_view Cord::FlattenSlowPath() {
 
 /* static */ bool Cord::GetFlatAux(CordRep* rep, absl::string_view* fragment) {
   assert(rep != nullptr);
-  if (rep->tag >= FLAT) {
+  if (rep->IsFlat()) {
     *fragment = absl::string_view(rep->flat()->Data(), rep->length);
     return true;
-  } else if (rep->tag == EXTERNAL) {
+  } else if (rep->IsExternal()) {
     *fragment = absl::string_view(rep->external()->base, rep->length);
     return true;
-  } else if (rep->tag == RING) {
-    return rep->ring()->IsFlat(fragment);
-  } else if (rep->tag == SUBSTRING) {
+  } else if (rep->IsBtree()) {
+    return rep->btree()->IsFlat(fragment);
+  } else if (rep->IsSubstring()) {
     CordRep* child = rep->substring()->child;
-    if (child->tag >= FLAT) {
+    if (child->IsFlat()) {
       *fragment = absl::string_view(
           child->flat()->Data() + rep->substring()->start, rep->length);
       return true;
-    } else if (child->tag == EXTERNAL) {
+    } else if (child->IsExternal()) {
       *fragment = absl::string_view(
           child->external()->base + rep->substring()->start, rep->length);
       return true;
-    } else if (child->tag == RING) {
-      return child->ring()->IsFlat(rep->substring()->start, rep->length,
-                                   fragment);
+    } else if (child->IsBtree()) {
+      return child->btree()->IsFlat(rep->substring()->start, rep->length,
+                                    fragment);
     }
   }
   return false;
@@ -1781,7 +1812,7 @@ absl::string_view Cord::FlattenSlowPath() {
 /* static */ void Cord::ForEachChunkAux(
     absl::cord_internal::CordRep* rep,
     absl::FunctionRef<void(absl::string_view)> callback) {
-  if (rep->tag == RING) {
+  if (rep->IsBtree()) {
     ChunkIterator it(rep), end;
     while (it != end) {
       callback(*it);
@@ -1797,7 +1828,7 @@ absl::string_view Cord::FlattenSlowPath() {
   absl::cord_internal::CordRep* stack[stack_max];
   absl::cord_internal::CordRep* current_node = rep;
   while (true) {
-    if (current_node->tag == CONCAT) {
+    if (current_node->IsConcat()) {
       if (stack_pos == stack_max) {
         // There's no more room on our stack array to add another right branch,
         // and the idea is to avoid allocations, so call this function
@@ -1844,37 +1875,29 @@ static void DumpNode(CordRep* rep, bool include_data, std::ostream* os,
     *os << "]";
     *os << " " << (IsRootBalanced(rep) ? 'b' : 'u');
     *os << " " << std::setw(indent) << "";
-    if (rep->tag == CONCAT) {
+    if (rep->IsConcat()) {
       *os << "CONCAT depth=" << Depth(rep) << "\n";
       indent += kIndentStep;
       indents.push_back(indent);
       stack.push_back(rep->concat()->right);
       rep = rep->concat()->left;
-    } else if (rep->tag == SUBSTRING) {
+    } else if (rep->IsSubstring()) {
       *os << "SUBSTRING @ " << rep->substring()->start << "\n";
       indent += kIndentStep;
       rep = rep->substring()->child;
     } else {  // Leaf or ring
-      if (rep->tag == EXTERNAL) {
+      if (rep->IsExternal()) {
         *os << "EXTERNAL [";
         if (include_data)
           *os << absl::CEscape(std::string(rep->external()->base, rep->length));
         *os << "]\n";
-      } else if (rep->tag >= FLAT) {
+      } else if (rep->IsFlat()) {
         *os << "FLAT cap=" << rep->flat()->Capacity() << " [";
         if (include_data)
           *os << absl::CEscape(std::string(rep->flat()->Data(), rep->length));
         *os << "]\n";
       } else {
-        assert(rep->tag == RING);
-        auto* ring = rep->ring();
-        *os << "RING, entries = " << ring->entries() << "\n";
-        CordRepRing::index_type head = ring->head();
-        do {
-          DumpNode(ring->entry_child(head), include_data, os,
-                   indent + kIndentStep);
-          head = ring->advance(head);
-        } while (head != ring->tail());
+        CordRepBtree::Dump(rep, /*label=*/ "", include_data, *os);
       }
       if (stack.empty()) break;
       rep = stack.back();
@@ -1906,7 +1929,7 @@ static bool VerifyNode(CordRep* root, CordRep* start_node,
       ABSL_INTERNAL_CHECK(node->length != 0, ReportError(root, node));
     }
 
-    if (node->tag == CONCAT) {
+    if (node->IsConcat()) {
       ABSL_INTERNAL_CHECK(node->concat()->left != nullptr,
                           ReportError(root, node));
       ABSL_INTERNAL_CHECK(node->concat()->right != nullptr,
@@ -1918,13 +1941,13 @@ static bool VerifyNode(CordRep* root, CordRep* start_node,
         worklist.push_back(node->concat()->right);
         worklist.push_back(node->concat()->left);
       }
-    } else if (node->tag >= FLAT) {
+    } else if (node->IsFlat()) {
       ABSL_INTERNAL_CHECK(node->length <= node->flat()->Capacity(),
                           ReportError(root, node));
-    } else if (node->tag == EXTERNAL) {
+    } else if (node->IsExternal()) {
       ABSL_INTERNAL_CHECK(node->external()->base != nullptr,
                           ReportError(root, node));
-    } else if (node->tag == SUBSTRING) {
+    } else if (node->IsSubstring()) {
       ABSL_INTERNAL_CHECK(
           node->substring()->start < node->substring()->child->length,
           ReportError(root, node));
@@ -1953,7 +1976,7 @@ static bool VerifyNode(CordRep* root, CordRep* start_node,
   while (true) {
     const CordRep* next_node = nullptr;
 
-    if (cur_node->tag == CONCAT) {
+    if (cur_node->IsConcat()) {
       total_mem_usage += sizeof(CordRepConcat);
       const CordRep* left = cur_node->concat()->left;
       if (!RepMemoryUsageLeaf(left, &total_mem_usage)) {
@@ -1967,18 +1990,21 @@ static bool VerifyNode(CordRep* root, CordRep* start_node,
         }
         next_node = right;
       }
-    } else if (cur_node->tag == RING) {
-      total_mem_usage += CordRepRing::AllocSize(cur_node->ring()->capacity());
-      const CordRepRing* ring = cur_node->ring();
-      CordRepRing::index_type pos = ring->head(), tail = ring->tail();
-      do {
-        CordRep* node = ring->entry_child(pos);
-        assert(node->tag >= FLAT || node->tag == EXTERNAL);
-        RepMemoryUsageLeaf(node, &total_mem_usage);
-      } while ((pos = ring->advance(pos)) != tail);
+    } else if (cur_node->IsBtree()) {
+      total_mem_usage += sizeof(CordRepBtree);
+      const CordRepBtree* node = cur_node->btree();
+      if (node->height() == 0) {
+        for (const CordRep* edge : node->Edges()) {
+          RepMemoryUsageDataEdge(edge, &total_mem_usage);
+        }
+      } else {
+        for (const CordRep* edge : node->Edges()) {
+          tree_stack.push_back(edge);
+        }
+      }
     } else {
       // Since cur_node is not a leaf or a concat node it must be a substring.
-      assert(cur_node->tag == SUBSTRING);
+      assert(cur_node->IsSubstring());
       total_mem_usage += sizeof(CordRepSubstring);
       next_node = cur_node->substring()->child;
       if (RepMemoryUsageLeaf(next_node, &total_mem_usage)) {
diff --git a/chromium/third_party/abseil-cpp/absl/strings/cord.h b/chromium/third_party/abseil-cpp/absl/strings/cord.h
index e758f1cdfb1..ac1832f0188 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/cord.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/cord.h
@@ -79,8 +79,9 @@
 #include "absl/functional/function_ref.h"
 #include "absl/meta/type_traits.h"
 #include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_btree_reader.h"
 #include "absl/strings/internal/cord_rep_ring.h"
-#include "absl/strings/internal/cord_rep_ring_reader.h"
 #include "absl/strings/internal/cordz_functions.h"
 #include "absl/strings/internal/cordz_info.h"
 #include "absl/strings/internal/cordz_statistics.h"
@@ -370,8 +371,8 @@ class Cord {
 
    private:
     using CordRep = absl::cord_internal::CordRep;
-    using CordRepRing = absl::cord_internal::CordRepRing;
-    using CordRepRingReader = absl::cord_internal::CordRepRingReader;
+    using CordRepBtree = absl::cord_internal::CordRepBtree;
+    using CordRepBtreeReader = absl::cord_internal::CordRepBtreeReader;
 
     // Stack of right children of concat nodes that we have to visit.
     // Keep this at the end of the structure to avoid cache-thrashing.
@@ -397,9 +398,9 @@ class Cord {
     // Stack specific operator++
     ChunkIterator& AdvanceStack();
 
-    // Ring buffer specific operator++
-    ChunkIterator& AdvanceRing();
-    void AdvanceBytesRing(size_t n);
+    // Btree specific operator++
+    ChunkIterator& AdvanceBtree();
+    void AdvanceBytesBtree(size_t n);
 
     // Iterates `n` bytes, where `n` is expected to be greater than or equal to
     // `current_chunk_.size()`.
@@ -415,8 +416,8 @@ class Cord {
     // The number of bytes left in the `Cord` over which we are iterating.
     size_t bytes_remaining_ = 0;
 
-    // Cord reader for ring buffers. Empty if not traversing a ring buffer.
-    CordRepRingReader ring_reader_;
+    // Cord reader for cord btrees. Empty if not traversing a btree.
+    CordRepBtreeReader btree_reader_;
 
     // See 'Stack' alias definition.
     Stack stack_of_right_children_;
@@ -1247,8 +1248,8 @@ inline bool Cord::StartsWith(absl::string_view rhs) const {
 }
 
 inline void Cord::ChunkIterator::InitTree(cord_internal::CordRep* tree) {
-  if (tree->tag == cord_internal::RING) {
-    current_chunk_ = ring_reader_.Reset(tree->ring());
+  if (tree->tag == cord_internal::BTREE) {
+    current_chunk_ = btree_reader_.Init(tree->btree());
     return;
   }
 
@@ -1271,20 +1272,20 @@ inline Cord::ChunkIterator::ChunkIterator(const Cord* cord)
   }
 }
 
-inline Cord::ChunkIterator& Cord::ChunkIterator::AdvanceRing() {
-  current_chunk_ = ring_reader_.Next();
+inline Cord::ChunkIterator& Cord::ChunkIterator::AdvanceBtree() {
+  current_chunk_ = btree_reader_.Next();
   return *this;
 }
 
-inline void Cord::ChunkIterator::AdvanceBytesRing(size_t n) {
+inline void Cord::ChunkIterator::AdvanceBytesBtree(size_t n) {
   assert(n >= current_chunk_.size());
   bytes_remaining_ -= n;
   if (bytes_remaining_) {
     if (n == current_chunk_.size()) {
-      current_chunk_ = ring_reader_.Next();
+      current_chunk_ = btree_reader_.Next();
     } else {
-      size_t offset = ring_reader_.length() - bytes_remaining_;
-      current_chunk_ = ring_reader_.Seek(offset);
+      size_t offset = btree_reader_.length() - bytes_remaining_;
+      current_chunk_ = btree_reader_.Seek(offset);
     }
   } else {
     current_chunk_ = {};
@@ -1297,7 +1298,7 @@ inline Cord::ChunkIterator& Cord::ChunkIterator::operator++() {
   assert(bytes_remaining_ >= current_chunk_.size());
   bytes_remaining_ -= current_chunk_.size();
   if (bytes_remaining_ > 0) {
-    return ring_reader_ ? AdvanceRing() : AdvanceStack();
+    return btree_reader_ ? AdvanceBtree() : AdvanceStack();
   } else {
     current_chunk_ = {};
   }
@@ -1339,7 +1340,7 @@ inline void Cord::ChunkIterator::AdvanceBytes(size_t n) {
   if (ABSL_PREDICT_TRUE(n < current_chunk_.size())) {
     RemoveChunkPrefix(n);
   } else if (n != 0) {
-    ring_reader_ ? AdvanceBytesRing(n) : AdvanceBytesSlowPath(n);
+    btree_reader_ ? AdvanceBytesBtree(n) : AdvanceBytesSlowPath(n);
   }
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/cord_ring_test.cc b/chromium/third_party/abseil-cpp/absl/strings/cord_ring_test.cc
index cc8fbaf995c..f1318595322 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/cord_ring_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/cord_ring_test.cc
@@ -223,7 +223,7 @@ CordRepExternal* MakeFakeExternal(size_t length) {
     std::string s;
     explicit Rep(size_t len) {
       this->tag = EXTERNAL;
-      this->base = this->storage;
+      this->base = reinterpret_cast<const char*>(this->storage);
       this->length = len;
       this->releaser_invoker = [](CordRepExternal* self) {
         delete static_cast<Rep*>(self);
@@ -275,7 +275,7 @@ CordRepConcat* MakeConcat(CordRep* left, CordRep* right, int depth = 0) {
 enum Composition { kMix, kAppend, kPrepend };
 
 Composition RandomComposition() {
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   return (rng() & 1) ? kMix : ((rng() & 1) ? kAppend : kPrepend);
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/cord_test.cc b/chromium/third_party/abseil-cpp/absl/strings/cord_test.cc
index 14eca155733..d029633812b 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/cord_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/cord_test.cc
@@ -206,7 +206,32 @@ class CordTestPeer {
 ABSL_NAMESPACE_END
 }  // namespace absl
 
-TEST(Cord, AllFlatSizes) {
+// The CordTest fixture runs all tests with and without Cord Btree enabled.
+class CordTest : public testing::TestWithParam<bool> {
+ public:
+  CordTest() : was_btree_(absl::cord_internal::cord_btree_enabled.load()) {
+    absl::cord_internal::cord_btree_enabled.store(UseBtree());
+  }
+  ~CordTest() override {
+    absl::cord_internal::cord_btree_enabled.store(was_btree_);
+  }
+
+  // Returns true if test is running with btree enabled.
+  bool UseBtree() const { return GetParam(); }
+
+  // Returns human readable string representation of the test parameter.
+  static std::string ToString(testing::TestParamInfo<bool> param) {
+    return param.param ? "Btree" : "Concat";
+  }
+
+ private:
+  const bool was_btree_;
+};
+
+INSTANTIATE_TEST_SUITE_P(WithParam, CordTest, testing::Bool(),
+                         CordTest::ToString);
+
+TEST_P(CordTest, AllFlatSizes) {
   using absl::strings_internal::CordTestAccess;
 
   for (size_t s = 0; s < CordTestAccess::MaxFlatLength(); s++) {
@@ -224,7 +249,7 @@ TEST(Cord, AllFlatSizes) {
 // We create a Cord at least 128GB in size using the fact that Cords can
 // internally reference-count; thus the Cord is enormous without actually
 // consuming very much memory.
-TEST(GigabyteCord, FromExternal) {
+TEST_P(CordTest, GigabyteCordFromExternal) {
   const size_t one_gig = 1024U * 1024U * 1024U;
   size_t max_size = 2 * one_gig;
   if (sizeof(max_size) > 4) max_size = 128 * one_gig;
@@ -273,7 +298,7 @@ static absl::Cord MakeExternalCord(int size) {
 extern bool my_unique_true_boolean;
 bool my_unique_true_boolean = true;
 
-TEST(Cord, Assignment) {
+TEST_P(CordTest, Assignment) {
   absl::Cord x(absl::string_view("hi there"));
   absl::Cord y(x);
   ASSERT_EQ(std::string(x), "hi there");
@@ -327,7 +352,7 @@ TEST(Cord, Assignment) {
   }
 }
 
-TEST(Cord, StartsEndsWith) {
+TEST_P(CordTest, StartsEndsWith) {
   absl::Cord x(absl::string_view("abcde"));
   absl::Cord empty("");
 
@@ -360,13 +385,13 @@ TEST(Cord, StartsEndsWith) {
   ASSERT_TRUE(!empty.EndsWith("xyz"));
 }
 
-TEST(Cord, Subcord) {
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+TEST_P(CordTest, Subcord) {
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   const std::string s = RandomLowercaseString(&rng, 1024);
 
   absl::Cord a;
   AppendWithFragments(s, &rng, &a);
-  ASSERT_EQ(s.size(), a.size());
+  ASSERT_EQ(s, std::string(a));
 
   // Check subcords of a, from a variety of interesting points.
   std::set<size_t> positions;
@@ -421,7 +446,7 @@ TEST(Cord, Subcord) {
   EXPECT_TRUE(sa.empty());
 }
 
-TEST(Cord, Swap) {
+TEST_P(CordTest, Swap) {
   absl::string_view a("Dexter");
   absl::string_view b("Mandark");
   absl::Cord x(a);
@@ -453,7 +478,7 @@ static void VerifyCopyToString(const absl::Cord& cord) {
   }
 }
 
-TEST(Cord, CopyToString) {
+TEST_P(CordTest, CopyToString) {
   VerifyCopyToString(absl::Cord());
   VerifyCopyToString(absl::Cord("small cord"));
   VerifyCopyToString(
@@ -461,45 +486,45 @@ TEST(Cord, CopyToString) {
                                 "copying ", "to ", "a ", "string."}));
 }
 
-TEST(TryFlat, Empty) {
+TEST_P(CordTest, TryFlatEmpty) {
   absl::Cord c;
   EXPECT_EQ(c.TryFlat(), "");
 }
 
-TEST(TryFlat, Flat) {
+TEST_P(CordTest, TryFlatFlat) {
   absl::Cord c("hello");
   EXPECT_EQ(c.TryFlat(), "hello");
 }
 
-TEST(TryFlat, SubstrInlined) {
+TEST_P(CordTest, TryFlatSubstrInlined) {
   absl::Cord c("hello");
   c.RemovePrefix(1);
   EXPECT_EQ(c.TryFlat(), "ello");
 }
 
-TEST(TryFlat, SubstrFlat) {
+TEST_P(CordTest, TryFlatSubstrFlat) {
   absl::Cord c("longer than 15 bytes");
   absl::Cord sub = absl::CordTestPeer::MakeSubstring(c, 1, c.size() - 1);
   EXPECT_EQ(sub.TryFlat(), "onger than 15 bytes");
 }
 
-TEST(TryFlat, Concat) {
+TEST_P(CordTest, TryFlatConcat) {
   absl::Cord c = absl::MakeFragmentedCord({"hel", "lo"});
   EXPECT_EQ(c.TryFlat(), absl::nullopt);
 }
 
-TEST(TryFlat, External) {
+TEST_P(CordTest, TryFlatExternal) {
   absl::Cord c = absl::MakeCordFromExternal("hell", [](absl::string_view) {});
   EXPECT_EQ(c.TryFlat(), "hell");
 }
 
-TEST(TryFlat, SubstrExternal) {
+TEST_P(CordTest, TryFlatSubstrExternal) {
   absl::Cord c = absl::MakeCordFromExternal("hell", [](absl::string_view) {});
   absl::Cord sub = absl::CordTestPeer::MakeSubstring(c, 1, c.size() - 1);
   EXPECT_EQ(sub.TryFlat(), "ell");
 }
 
-TEST(TryFlat, SubstrConcat) {
+TEST_P(CordTest, TryFlatSubstrConcat) {
   absl::Cord c = absl::MakeFragmentedCord({"hello", " world"});
   absl::Cord sub = absl::CordTestPeer::MakeSubstring(c, 1, c.size() - 1);
   EXPECT_EQ(sub.TryFlat(), absl::nullopt);
@@ -507,7 +532,7 @@ TEST(TryFlat, SubstrConcat) {
   EXPECT_EQ(c.TryFlat(), absl::nullopt);
 }
 
-TEST(TryFlat, CommonlyAssumedInvariants) {
+TEST_P(CordTest, TryFlatCommonlyAssumedInvariants) {
   // The behavior tested below is not part of the API contract of Cord, but it's
   // something we intend to be true in our current implementation.  This test
   // exists to detect and prevent accidental breakage of the implementation.
@@ -563,14 +588,14 @@ static void VerifyFlatten(absl::Cord c) {
   EXPECT_TRUE(IsFlat(c));
 }
 
-TEST(Cord, Flatten) {
+TEST_P(CordTest, Flatten) {
   VerifyFlatten(absl::Cord());
   VerifyFlatten(absl::Cord("small cord"));
   VerifyFlatten(absl::Cord("larger than small buffer optimization"));
   VerifyFlatten(absl::MakeFragmentedCord({"small ", "fragmented ", "cord"}));
 
   // Test with a cord that is longer than the largest flat buffer
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   VerifyFlatten(absl::Cord(RandomLowercaseString(&rng, 8192)));
 }
 
@@ -617,7 +642,7 @@ class TestData {
 };
 }  // namespace
 
-TEST(Cord, MultipleLengths) {
+TEST_P(CordTest, MultipleLengths) {
   TestData d;
   for (size_t i = 0; i < d.size(); i++) {
     std::string a = d.data(i);
@@ -693,7 +718,7 @@ TEST(Cord, MultipleLengths) {
 
 namespace {
 
-TEST(Cord, RemoveSuffixWithExternalOrSubstring) {
+TEST_P(CordTest, RemoveSuffixWithExternalOrSubstring) {
   absl::Cord cord = absl::MakeCordFromExternal(
       "foo bar baz", [](absl::string_view s) { DoNothing(s, nullptr); });
 
@@ -708,7 +733,7 @@ TEST(Cord, RemoveSuffixWithExternalOrSubstring) {
   EXPECT_EQ("foo", std::string(cord));
 }
 
-TEST(Cord, RemoveSuffixMakesZeroLengthNode) {
+TEST_P(CordTest, RemoveSuffixMakesZeroLengthNode) {
   absl::Cord c;
   c.Append(absl::Cord(std::string(100, 'x')));
   absl::Cord other_ref = c;  // Prevent inplace appends
@@ -735,7 +760,7 @@ absl::Cord CordWithZedBlock(size_t size) {
 }
 
 // Establish that ZedBlock does what we think it does.
-TEST(CordSpliceTest, ZedBlock) {
+TEST_P(CordTest, CordSpliceTestZedBlock) {
   absl::Cord blob = CordWithZedBlock(10);
   EXPECT_EQ(10, blob.size());
   std::string s;
@@ -743,7 +768,7 @@ TEST(CordSpliceTest, ZedBlock) {
   EXPECT_EQ("zzzzzzzzzz", s);
 }
 
-TEST(CordSpliceTest, ZedBlock0) {
+TEST_P(CordTest, CordSpliceTestZedBlock0) {
   absl::Cord blob = CordWithZedBlock(0);
   EXPECT_EQ(0, blob.size());
   std::string s;
@@ -751,7 +776,7 @@ TEST(CordSpliceTest, ZedBlock0) {
   EXPECT_EQ("", s);
 }
 
-TEST(CordSpliceTest, ZedBlockSuffix1) {
+TEST_P(CordTest, CordSpliceTestZedBlockSuffix1) {
   absl::Cord blob = CordWithZedBlock(10);
   EXPECT_EQ(10, blob.size());
   absl::Cord suffix(blob);
@@ -763,7 +788,7 @@ TEST(CordSpliceTest, ZedBlockSuffix1) {
 }
 
 // Remove all of a prefix block
-TEST(CordSpliceTest, ZedBlockSuffix0) {
+TEST_P(CordTest, CordSpliceTestZedBlockSuffix0) {
   absl::Cord blob = CordWithZedBlock(10);
   EXPECT_EQ(10, blob.size());
   absl::Cord suffix(blob);
@@ -795,7 +820,7 @@ absl::Cord SpliceCord(const absl::Cord& blob, int64_t offset,
 }
 
 // Taking an empty suffix of a block breaks appending.
-TEST(CordSpliceTest, RemoveEntireBlock1) {
+TEST_P(CordTest, CordSpliceTestRemoveEntireBlock1) {
   absl::Cord zero = CordWithZedBlock(10);
   absl::Cord suffix(zero);
   suffix.RemovePrefix(10);
@@ -803,7 +828,7 @@ TEST(CordSpliceTest, RemoveEntireBlock1) {
   result.Append(suffix);
 }
 
-TEST(CordSpliceTest, RemoveEntireBlock2) {
+TEST_P(CordTest, CordSpliceTestRemoveEntireBlock2) {
   absl::Cord zero = CordWithZedBlock(10);
   absl::Cord prefix(zero);
   prefix.RemoveSuffix(10);
@@ -813,7 +838,7 @@ TEST(CordSpliceTest, RemoveEntireBlock2) {
   result.Append(suffix);
 }
 
-TEST(CordSpliceTest, RemoveEntireBlock3) {
+TEST_P(CordTest, CordSpliceTestRemoveEntireBlock3) {
   absl::Cord blob = CordWithZedBlock(10);
   absl::Cord block = BigCord(10, 'b');
   blob = SpliceCord(blob, 0, block);
@@ -844,7 +869,7 @@ void VerifyComparison(const CordCompareTestCase& test_case) {
       << "LHS=" << rhs_string << "; RHS=" << lhs_string;
 }
 
-TEST(Cord, Compare) {
+TEST_P(CordTest, Compare) {
   absl::Cord subcord("aaaaaBBBBBcccccDDDDD");
   subcord = subcord.Subcord(3, 10);
 
@@ -907,7 +932,7 @@ TEST(Cord, Compare) {
   }
 }
 
-TEST(Cord, CompareAfterAssign) {
+TEST_P(CordTest, CompareAfterAssign) {
   absl::Cord a("aaaaaa1111111");
   absl::Cord b("aaaaaa2222222");
   a = "cccccc";
@@ -936,8 +961,8 @@ static void TestCompare(const absl::Cord& c, const absl::Cord& d,
   EXPECT_EQ(expected, sign(c.Compare(d))) << c << ", " << d;
 }
 
-TEST(Compare, ComparisonIsUnsigned) {
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+TEST_P(CordTest, CompareComparisonIsUnsigned) {
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   std::uniform_int_distribution<uint32_t> uniform_uint8(0, 255);
   char x = static_cast<char>(uniform_uint8(rng));
   TestCompare(
@@ -945,9 +970,9 @@ TEST(Compare, ComparisonIsUnsigned) {
       absl::Cord(std::string(GetUniformRandomUpTo(&rng, 100), x ^ 0x80)), &rng);
 }
 
-TEST(Compare, RandomComparisons) {
+TEST_P(CordTest, CompareRandomComparisons) {
   const int kIters = 5000;
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
 
   int n = GetUniformRandomUpTo(&rng, 5000);
   absl::Cord a[] = {MakeExternalCord(n),
@@ -1003,43 +1028,43 @@ void CompareOperators() {
   EXPECT_FALSE(b <= a);
 }
 
-TEST(ComparisonOperators, Cord_Cord) {
+TEST_P(CordTest, ComparisonOperators_Cord_Cord) {
   CompareOperators<absl::Cord, absl::Cord>();
 }
 
-TEST(ComparisonOperators, Cord_StringPiece) {
+TEST_P(CordTest, ComparisonOperators_Cord_StringPiece) {
   CompareOperators<absl::Cord, absl::string_view>();
 }
 
-TEST(ComparisonOperators, StringPiece_Cord) {
+TEST_P(CordTest, ComparisonOperators_StringPiece_Cord) {
   CompareOperators<absl::string_view, absl::Cord>();
 }
 
-TEST(ComparisonOperators, Cord_string) {
+TEST_P(CordTest, ComparisonOperators_Cord_string) {
   CompareOperators<absl::Cord, std::string>();
 }
 
-TEST(ComparisonOperators, string_Cord) {
+TEST_P(CordTest, ComparisonOperators_string_Cord) {
   CompareOperators<std::string, absl::Cord>();
 }
 
-TEST(ComparisonOperators, stdstring_Cord) {
+TEST_P(CordTest, ComparisonOperators_stdstring_Cord) {
   CompareOperators<std::string, absl::Cord>();
 }
 
-TEST(ComparisonOperators, Cord_stdstring) {
+TEST_P(CordTest, ComparisonOperators_Cord_stdstring) {
   CompareOperators<absl::Cord, std::string>();
 }
 
-TEST(ComparisonOperators, charstar_Cord) {
+TEST_P(CordTest, ComparisonOperators_charstar_Cord) {
   CompareOperators<const char*, absl::Cord>();
 }
 
-TEST(ComparisonOperators, Cord_charstar) {
+TEST_P(CordTest, ComparisonOperators_Cord_charstar) {
   CompareOperators<absl::Cord, const char*>();
 }
 
-TEST(ConstructFromExternal, ReleaserInvoked) {
+TEST_P(CordTest, ConstructFromExternalReleaserInvoked) {
   // Empty external memory means the releaser should be called immediately.
   {
     bool invoked = false;
@@ -1081,8 +1106,8 @@ TEST(ConstructFromExternal, ReleaserInvoked) {
   }
 }
 
-TEST(ConstructFromExternal, CompareContents) {
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+TEST_P(CordTest, ConstructFromExternalCompareContents) {
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
 
   for (int length = 1; length <= 2048; length *= 2) {
     std::string data = RandomLowercaseString(&rng, length);
@@ -1097,8 +1122,8 @@ TEST(ConstructFromExternal, CompareContents) {
   }
 }
 
-TEST(ConstructFromExternal, LargeReleaser) {
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+TEST_P(CordTest, ConstructFromExternalLargeReleaser) {
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   constexpr size_t kLength = 256;
   std::string data = RandomLowercaseString(&rng, kLength);
   std::array<char, kLength> data_array;
@@ -1112,7 +1137,7 @@ TEST(ConstructFromExternal, LargeReleaser) {
   EXPECT_TRUE(invoked);
 }
 
-TEST(ConstructFromExternal, FunctionPointerReleaser) {
+TEST_P(CordTest, ConstructFromExternalFunctionPointerReleaser) {
   static absl::string_view data("hello world");
   static bool invoked;
   auto* releaser =
@@ -1129,7 +1154,7 @@ TEST(ConstructFromExternal, FunctionPointerReleaser) {
   EXPECT_TRUE(invoked);
 }
 
-TEST(ConstructFromExternal, MoveOnlyReleaser) {
+TEST_P(CordTest, ConstructFromExternalMoveOnlyReleaser) {
   struct Releaser {
     explicit Releaser(bool* invoked) : invoked(invoked) {}
     Releaser(Releaser&& other) noexcept : invoked(other.invoked) {}
@@ -1143,20 +1168,20 @@ TEST(ConstructFromExternal, MoveOnlyReleaser) {
   EXPECT_TRUE(invoked);
 }
 
-TEST(ConstructFromExternal, NoArgLambda) {
+TEST_P(CordTest, ConstructFromExternalNoArgLambda) {
   bool invoked = false;
   (void)absl::MakeCordFromExternal("dummy", [&invoked]() { invoked = true; });
   EXPECT_TRUE(invoked);
 }
 
-TEST(ConstructFromExternal, StringViewArgLambda) {
+TEST_P(CordTest, ConstructFromExternalStringViewArgLambda) {
   bool invoked = false;
   (void)absl::MakeCordFromExternal(
       "dummy", [&invoked](absl::string_view) { invoked = true; });
   EXPECT_TRUE(invoked);
 }
 
-TEST(ConstructFromExternal, NonTrivialReleaserDestructor) {
+TEST_P(CordTest, ConstructFromExternalNonTrivialReleaserDestructor) {
   struct Releaser {
     explicit Releaser(bool* destroyed) : destroyed(destroyed) {}
     ~Releaser() { *destroyed = true; }
@@ -1171,7 +1196,7 @@ TEST(ConstructFromExternal, NonTrivialReleaserDestructor) {
   EXPECT_TRUE(destroyed);
 }
 
-TEST(ConstructFromExternal, ReferenceQualifierOverloads) {
+TEST_P(CordTest, ConstructFromExternalReferenceQualifierOverloads) {
   struct Releaser {
     void operator()(absl::string_view) & { *lvalue_invoked = true; }
     void operator()(absl::string_view) && { *rvalue_invoked = true; }
@@ -1199,7 +1224,7 @@ TEST(ConstructFromExternal, ReferenceQualifierOverloads) {
   EXPECT_TRUE(rvalue_invoked);
 }
 
-TEST(ExternalMemory, BasicUsage) {
+TEST_P(CordTest, ExternalMemoryBasicUsage) {
   static const char* strings[] = {"", "hello", "there"};
   for (const char* str : strings) {
     absl::Cord dst("(prefix)");
@@ -1210,7 +1235,7 @@ TEST(ExternalMemory, BasicUsage) {
   }
 }
 
-TEST(ExternalMemory, RemovePrefixSuffix) {
+TEST_P(CordTest, ExternalMemoryRemovePrefixSuffix) {
   // Exhaustively try all sub-strings.
   absl::Cord cord = MakeComposite();
   std::string s = std::string(cord);
@@ -1225,7 +1250,7 @@ TEST(ExternalMemory, RemovePrefixSuffix) {
   }
 }
 
-TEST(ExternalMemory, Get) {
+TEST_P(CordTest, ExternalMemoryGet) {
   absl::Cord cord("hello");
   AddExternalMemory(" world!", &cord);
   AddExternalMemory(" how are ", &cord);
@@ -1244,16 +1269,16 @@ TEST(ExternalMemory, Get) {
 // Additionally we have some whiteboxed expectations based on our knowledge of
 // the layout and size of empty and inlined cords, and flat nodes.
 
-TEST(CordMemoryUsage, Empty) {
+TEST_P(CordTest, CordMemoryUsageEmpty) {
   EXPECT_EQ(sizeof(absl::Cord), absl::Cord().EstimatedMemoryUsage());
 }
 
-TEST(CordMemoryUsage, Embedded) {
+TEST_P(CordTest, CordMemoryUsageEmbedded) {
   absl::Cord a("hello");
   EXPECT_EQ(a.EstimatedMemoryUsage(), sizeof(absl::Cord));
 }
 
-TEST(CordMemoryUsage, EmbeddedAppend) {
+TEST_P(CordTest, CordMemoryUsageEmbeddedAppend) {
   absl::Cord a("a");
   absl::Cord b("bcd");
   EXPECT_EQ(b.EstimatedMemoryUsage(), sizeof(absl::Cord));
@@ -1261,7 +1286,7 @@ TEST(CordMemoryUsage, EmbeddedAppend) {
   EXPECT_EQ(a.EstimatedMemoryUsage(), sizeof(absl::Cord));
 }
 
-TEST(CordMemoryUsage, ExternalMemory) {
+TEST_P(CordTest, CordMemoryUsageExternalMemory) {
   static const int kLength = 1000;
   absl::Cord cord;
   AddExternalMemory(std::string(kLength, 'x'), &cord);
@@ -1269,14 +1294,14 @@ TEST(CordMemoryUsage, ExternalMemory) {
   EXPECT_LE(cord.EstimatedMemoryUsage(), kLength * 1.5);
 }
 
-TEST(CordMemoryUsage, Flat) {
+TEST_P(CordTest, CordMemoryUsageFlat) {
   static const int kLength = 125;
   absl::Cord a(std::string(kLength, 'a'));
   EXPECT_GT(a.EstimatedMemoryUsage(), kLength);
   EXPECT_LE(a.EstimatedMemoryUsage(), kLength * 1.5);
 }
 
-TEST(CordMemoryUsage, AppendFlat) {
+TEST_P(CordTest, CordMemoryUsageAppendFlat) {
   using absl::strings_internal::CordTestAccess;
   absl::Cord a(std::string(CordTestAccess::MaxFlatLength(), 'a'));
   size_t length = a.EstimatedMemoryUsage();
@@ -1286,9 +1311,32 @@ TEST(CordMemoryUsage, AppendFlat) {
   EXPECT_LE(delta, CordTestAccess::MaxFlatLength() * 1.5);
 }
 
+TEST_P(CordTest, CordMemoryUsageAppendExternal) {
+  static const int kLength = 1000;
+  using absl::strings_internal::CordTestAccess;
+  absl::Cord a(std::string(CordTestAccess::MaxFlatLength(), 'a'));
+  size_t length = a.EstimatedMemoryUsage();
+  AddExternalMemory(std::string(kLength, 'b'), &a);
+  size_t delta = a.EstimatedMemoryUsage() - length;
+  EXPECT_GT(delta, kLength);
+  EXPECT_LE(delta, kLength * 1.5);
+}
+
+TEST_P(CordTest, CordMemoryUsageSubString) {
+  static const int kLength = 2000;
+  using absl::strings_internal::CordTestAccess;
+  absl::Cord a(std::string(kLength, 'a'));
+  size_t length = a.EstimatedMemoryUsage();
+  AddExternalMemory(std::string(kLength, 'b'), &a);
+  absl::Cord b = a.Subcord(0, kLength + kLength / 2);
+  size_t delta = b.EstimatedMemoryUsage() - length;
+  EXPECT_GT(delta, kLength);
+  EXPECT_LE(delta, kLength * 1.5);
+}
+
 // Regtest for a change that had to be rolled back because it expanded out
 // of the InlineRep too soon, which was observable through MemoryUsage().
-TEST(CordMemoryUsage, InlineRep) {
+TEST_P(CordTest, CordMemoryUsageInlineRep) {
   constexpr size_t kMaxInline = 15;  // Cord::InlineRep::N
   const std::string small_string(kMaxInline, 'x');
   absl::Cord c1(small_string);
@@ -1302,7 +1350,7 @@ TEST(CordMemoryUsage, InlineRep) {
 }  // namespace
 
 // Regtest for 7510292 (fix a bug introduced by 7465150)
-TEST(Cord, Concat_Append) {
+TEST_P(CordTest, Concat_Append) {
   // Create a rep of type CONCAT
   absl::Cord s1("foobarbarbarbarbar");
   s1.Append("abcdefgabcdefgabcdefgabcdefgabcdefgabcdefgabcdefg");
@@ -1317,13 +1365,13 @@ TEST(Cord, Concat_Append) {
   EXPECT_EQ(s2.size(), size + 1);
 }
 
-TEST(Cord, DiabolicalGrowth) {
+TEST_P(CordTest, DiabolicalGrowth) {
   // This test exercises a diabolical Append(<one char>) on a cord, making the
   // cord shared before each Append call resulting in a terribly fragmented
   // resulting cord.
   // TODO(b/183983616): Apply some minimum compaction when copying a shared
   // source cord into a mutable copy for updates in CordRepRing.
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   const std::string expected = RandomLowercaseString(&rng, 5000);
   absl::Cord cord;
   for (char c : expected) {
@@ -1337,7 +1385,7 @@ TEST(Cord, DiabolicalGrowth) {
                cord.EstimatedMemoryUsage());
 }
 
-TEST(MakeFragmentedCord, MakeFragmentedCordFromInitializerList) {
+TEST_P(CordTest, MakeFragmentedCordFromInitializerList) {
   absl::Cord fragmented =
       absl::MakeFragmentedCord({"A ", "fragmented ", "Cord"});
 
@@ -1357,7 +1405,7 @@ TEST(MakeFragmentedCord, MakeFragmentedCordFromInitializerList) {
   ASSERT_TRUE(++chunk_it == fragmented.chunk_end());
 }
 
-TEST(MakeFragmentedCord, MakeFragmentedCordFromVector) {
+TEST_P(CordTest, MakeFragmentedCordFromVector) {
   std::vector<absl::string_view> chunks = {"A ", "fragmented ", "Cord"};
   absl::Cord fragmented = absl::MakeFragmentedCord(chunks);
 
@@ -1377,7 +1425,7 @@ TEST(MakeFragmentedCord, MakeFragmentedCordFromVector) {
   ASSERT_TRUE(++chunk_it == fragmented.chunk_end());
 }
 
-TEST(CordChunkIterator, Traits) {
+TEST_P(CordTest, CordChunkIteratorTraits) {
   static_assert(std::is_copy_constructible<absl::Cord::ChunkIterator>::value,
                 "");
   static_assert(std::is_copy_assignable<absl::Cord::ChunkIterator>::value, "");
@@ -1458,7 +1506,7 @@ static void VerifyChunkIterator(const absl::Cord& cord,
   EXPECT_TRUE(post_iter == cord.chunk_end());  // NOLINT
 }
 
-TEST(CordChunkIterator, Operations) {
+TEST_P(CordTest, CordChunkIteratorOperations) {
   absl::Cord empty_cord;
   VerifyChunkIterator(empty_cord, 0);
 
@@ -1483,7 +1531,7 @@ TEST(CordChunkIterator, Operations) {
     VerifyChunkIterator(reused_nodes_cord, expected_chunks);
   }
 
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   absl::Cord flat_cord(RandomLowercaseString(&rng, 256));
   absl::Cord subcords;
   for (int i = 0; i < 128; ++i) subcords.Prepend(flat_cord.Subcord(i, 128));
@@ -1621,14 +1669,14 @@ TEST(CordCharIterator, Operations) {
     VerifyCharIterator(reused_nodes_cord);
   }
 
-  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  RandomEngine rng(GTEST_FLAG_GET(random_seed));
   absl::Cord flat_cord(RandomLowercaseString(&rng, 256));
   absl::Cord subcords;
   for (int i = 0; i < 4; ++i) subcords.Prepend(flat_cord.Subcord(16 * i, 128));
   VerifyCharIterator(subcords);
 }
 
-TEST(Cord, StreamingOutput) {
+TEST_P(CordTest, StreamingOutput) {
   absl::Cord c =
       absl::MakeFragmentedCord({"A ", "small ", "fragmented ", "Cord", "."});
   std::stringstream output;
@@ -1636,7 +1684,7 @@ TEST(Cord, StreamingOutput) {
   EXPECT_EQ("A small fragmented Cord.", output.str());
 }
 
-TEST(Cord, ForEachChunk) {
+TEST_P(CordTest, ForEachChunk) {
   for (int num_elements : {1, 10, 200}) {
     SCOPED_TRACE(num_elements);
     std::vector<std::string> cord_chunks;
@@ -1654,7 +1702,7 @@ TEST(Cord, ForEachChunk) {
   }
 }
 
-TEST(Cord, SmallBufferAssignFromOwnData) {
+TEST_P(CordTest, SmallBufferAssignFromOwnData) {
   constexpr size_t kMaxInline = 15;
   std::string contents = "small buff cord";
   EXPECT_EQ(contents.size(), kMaxInline);
@@ -1669,7 +1717,7 @@ TEST(Cord, SmallBufferAssignFromOwnData) {
   }
 }
 
-TEST(Cord, Format) {
+TEST_P(CordTest, Format) {
   absl::Cord c;
   absl::Format(&c, "There were %04d little %s.", 3, "pigs");
   EXPECT_EQ(c, "There were 0003 little pigs.");
@@ -1770,7 +1818,7 @@ struct LongView {
 };
 
 
-TEST(Cord, ConstinitConstructor) {
+TEST_P(CordTest, ConstinitConstructor) {
   TestConstinitConstructor(
       absl::strings_internal::MakeStringConstant(ShortView{}));
   TestConstinitConstructor(
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.cc
index 905ffd0cc16..1767e6fcc50 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.cc
@@ -18,6 +18,7 @@
 #include <memory>
 
 #include "absl/container/inlined_vector.h"
+#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_flat.h"
 #include "absl/strings/internal/cord_rep_ring.h"
 
@@ -25,10 +26,12 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace cord_internal {
 
+ABSL_CONST_INIT std::atomic<bool> cord_btree_enabled(kCordEnableBtreeDefault);
 ABSL_CONST_INIT std::atomic<bool> cord_ring_buffer_enabled(
     kCordEnableRingBufferDefault);
 ABSL_CONST_INIT std::atomic<bool> shallow_subcords_enabled(
     kCordShallowSubcordsDefault);
+ABSL_CONST_INIT std::atomic<bool> cord_btree_exhaustive_validation(false);
 
 void CordRep::Destroy(CordRep* rep) {
   assert(rep != nullptr);
@@ -49,6 +52,9 @@ void CordRep::Destroy(CordRep* rep) {
         rep = left;
         continue;
       }
+    } else if (rep->tag == BTREE) {
+      CordRepBtree::Destroy(rep->btree());
+      rep = nullptr;
     } else if (rep->tag == RING) {
       CordRepRing::Destroy(rep->ring());
       rep = nullptr;
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.h
index 813b3f35270..b7f3f4c0fee 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_internal.h
@@ -37,13 +37,25 @@ class CordzInfo;
 
 // Default feature enable states for cord ring buffers
 enum CordFeatureDefaults {
+  kCordEnableBtreeDefault = false,
   kCordEnableRingBufferDefault = false,
   kCordShallowSubcordsDefault = false
 };
 
+extern std::atomic<bool> cord_btree_enabled;
 extern std::atomic<bool> cord_ring_buffer_enabled;
 extern std::atomic<bool> shallow_subcords_enabled;
 
+// `cord_btree_exhaustive_validation` can be set to force exhaustive validation
+// in debug assertions, and code that calls `IsValid()` explicitly. By default,
+// assertions should be relatively cheap and AssertValid() can easily lead to
+// O(n^2) complexity as recursive / full tree validation is O(n).
+extern std::atomic<bool> cord_btree_exhaustive_validation;
+
+inline void enable_cord_btree(bool enable) {
+  cord_btree_enabled.store(enable, std::memory_order_relaxed);
+}
+
 inline void enable_cord_ring_buffer(bool enable) {
   cord_ring_buffer_enabled.store(enable, std::memory_order_relaxed);
 }
@@ -150,24 +162,37 @@ struct CordRepExternal;
 struct CordRepFlat;
 struct CordRepSubstring;
 class CordRepRing;
+class CordRepBtree;
 
 // Various representations that we allow
 enum CordRepKind {
   CONCAT = 0,
-  EXTERNAL = 1,
-  SUBSTRING = 2,
+  SUBSTRING = 1,
+  BTREE = 2,
   RING = 3,
+  EXTERNAL = 4,
 
   // We have different tags for different sized flat arrays,
-  // starting with FLAT, and limited to MAX_FLAT_TAG. The 224 value is based on
+  // starting with FLAT, and limited to MAX_FLAT_TAG. The 225 value is based on
   // the current 'size to tag' encoding of 8 / 32 bytes. If a new tag is needed
   // in the future, then 'FLAT' and 'MAX_FLAT_TAG' should be adjusted as well
   // as the Tag <---> Size logic so that FLAT stil represents the minimum flat
   // allocation size. (32 bytes as of now).
-  FLAT = 4,
-  MAX_FLAT_TAG = 224
+  FLAT = 5,
+  MAX_FLAT_TAG = 225
 };
 
+// There are various locations where we want to check if some rep is a 'plain'
+// data edge, i.e. an external or flat rep. By having FLAT == EXTERNAL + 1, we
+// can perform this check in a single branch as 'tag >= EXTERNAL'
+// Likewise, we have some locations where we check for 'ring or external/flat',
+// so likewise align RING to EXTERNAL.
+// Note that we can leave this optimization to the compiler. The compiler will
+// DTRT when it sees a condition like `tag == EXTERNAL || tag >= FLAT`.
+static_assert(RING == BTREE + 1, "BTREE and RING not consecutive");
+static_assert(EXTERNAL == RING + 1, "BTREE and EXTERNAL not consecutive");
+static_assert(FLAT == EXTERNAL + 1, "EXTERNAL and FLAT not consecutive");
+
 struct CordRep {
   CordRep() = default;
   constexpr CordRep(Refcount::Immortal immortal, size_t l)
@@ -180,7 +205,24 @@ struct CordRep {
   // If tag < FLAT, it represents CordRepKind and indicates the type of node.
   // Otherwise, the node type is CordRepFlat and the tag is the encoded size.
   uint8_t tag;
-  char storage[1];  // Starting point for flat array: MUST BE LAST FIELD
+
+  // `storage` provides two main purposes:
+  // - the starting point for FlatCordRep.Data() [flexible-array-member]
+  // - 3 bytes of additional storage for use by derived classes.
+  // The latter is used by CordrepConcat and CordRepBtree. CordRepConcat stores
+  // a 'depth' value in storage[0], and the (future) CordRepBtree class stores
+  // `height`, `begin` and `end` in the 3 entries. Otherwise we would need to
+  // allocate room for these in the derived class, as not all compilers reuse
+  // padding space from the base class (clang and gcc do, MSVC does not, etc)
+  uint8_t storage[3];
+
+  // Returns true if this instance's tag matches the requested type.
+  constexpr bool IsRing() const { return tag == RING; }
+  constexpr bool IsConcat() const { return tag == CONCAT; }
+  constexpr bool IsSubstring() const { return tag == SUBSTRING; }
+  constexpr bool IsExternal() const { return tag == EXTERNAL; }
+  constexpr bool IsFlat() const { return tag >= FLAT; }
+  constexpr bool IsBtree() const { return tag == BTREE; }
 
   inline CordRepRing* ring();
   inline const CordRepRing* ring() const;
@@ -192,6 +234,8 @@ struct CordRep {
   inline const CordRepExternal* external() const;
   inline CordRepFlat* flat();
   inline const CordRepFlat* flat() const;
+  inline CordRepBtree* btree();
+  inline const CordRepBtree* btree() const;
 
   // --------------------------------------------------------------------
   // Memory management
@@ -212,8 +256,8 @@ struct CordRepConcat : public CordRep {
   CordRep* left;
   CordRep* right;
 
-  uint8_t depth() const { return static_cast<uint8_t>(storage[0]); }
-  void set_depth(uint8_t depth) { storage[0] = static_cast<char>(depth); }
+  uint8_t depth() const { return storage[0]; }
+  void set_depth(uint8_t depth) { storage[0] = depth; }
 };
 
 struct CordRepSubstring : public CordRep {
@@ -240,7 +284,7 @@ struct CordRepExternal : public CordRep {
   ExternalReleaserInvoker releaser_invoker;
 
   // Deletes (releases) the external rep.
-  // Requires rep != nullptr and rep->tag == EXTERNAL
+  // Requires rep != nullptr and rep->IsExternal()
   static void Delete(CordRep* rep);
 };
 
@@ -283,7 +327,7 @@ struct CordRepExternalImpl
 };
 
 inline void CordRepExternal::Delete(CordRep* rep) {
-  assert(rep != nullptr && rep->tag == EXTERNAL);
+  assert(rep != nullptr && rep->IsExternal());
   auto* rep_external = static_cast<CordRepExternal*>(rep);
   assert(rep_external->releaser_invoker != nullptr);
   rep_external->releaser_invoker(rep_external);
@@ -494,32 +538,32 @@ class InlineData {
 static_assert(sizeof(InlineData) == kMaxInline + 1, "");
 
 inline CordRepConcat* CordRep::concat() {
-  assert(tag == CONCAT);
+  assert(IsConcat());
   return static_cast<CordRepConcat*>(this);
 }
 
 inline const CordRepConcat* CordRep::concat() const {
-  assert(tag == CONCAT);
+  assert(IsConcat());
   return static_cast<const CordRepConcat*>(this);
 }
 
 inline CordRepSubstring* CordRep::substring() {
-  assert(tag == SUBSTRING);
+  assert(IsSubstring());
   return static_cast<CordRepSubstring*>(this);
 }
 
 inline const CordRepSubstring* CordRep::substring() const {
-  assert(tag == SUBSTRING);
+  assert(IsSubstring());
   return static_cast<const CordRepSubstring*>(this);
 }
 
 inline CordRepExternal* CordRep::external() {
-  assert(tag == EXTERNAL);
+  assert(IsExternal());
   return static_cast<CordRepExternal*>(this);
 }
 
 inline const CordRepExternal* CordRep::external() const {
-  assert(tag == EXTERNAL);
+  assert(IsExternal());
   return static_cast<const CordRepExternal*>(this);
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.cc
new file mode 100644
index 00000000000..8fe589fa6a4
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.cc
@@ -0,0 +1,954 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree.h"
+
+#include <cassert>
+#include <cstdint>
+#include <iostream>
+#include <string>
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_consume.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+constexpr size_t CordRepBtree::kMaxCapacity;  // NOLINT: needed for c++ < c++17
+
+namespace {
+
+using NodeStack = CordRepBtree * [CordRepBtree::kMaxDepth];
+using EdgeType = CordRepBtree::EdgeType;
+using OpResult = CordRepBtree::OpResult;
+using CopyResult = CordRepBtree::CopyResult;
+
+constexpr auto kFront = CordRepBtree::kFront;
+constexpr auto kBack = CordRepBtree::kBack;
+
+inline bool exhaustive_validation() {
+  return cord_btree_exhaustive_validation.load(std::memory_order_relaxed);
+}
+
+// Implementation of the various 'Dump' functions.
+// Prints the entire tree structure or 'rep'. External callers should
+// not specify 'depth' and leave it to its default (0) value.
+// Rep may be a CordRepBtree tree, or a SUBSTRING / EXTERNAL / FLAT node.
+void DumpAll(const CordRep* rep, bool include_contents, std::ostream& stream,
+             int depth = 0) {
+  // Allow for full height trees + substring -> flat / external nodes.
+  assert(depth <= CordRepBtree::kMaxDepth + 2);
+  std::string sharing = const_cast<CordRep*>(rep)->refcount.IsOne()
+                            ? std::string("Private")
+                            : absl::StrCat("Shared(", rep->refcount.Get(), ")");
+  std::string sptr = absl::StrCat("0x", absl::Hex(rep));
+
+  // Dumps the data contents of `rep` if `include_contents` is true.
+  // Always emits a new line character.
+  auto maybe_dump_data = [&stream, include_contents](const CordRep* r) {
+    if (include_contents) {
+      // Allow for up to 60 wide display of content data, which with some
+      // indentation and prefix / labels keeps us within roughly 80-100 wide.
+      constexpr size_t kMaxDataLength = 60;
+      stream << ", data = \""
+             << CordRepBtree::EdgeData(r).substr(0, kMaxDataLength)
+             << (r->length > kMaxDataLength ? "\"..." : "\"");
+    }
+    stream << '\n';
+  };
+
+  // For each level, we print the 'shared/private' state and the rep pointer,
+  // indented by two spaces per recursive depth.
+  stream << std::string(depth * 2, ' ') << sharing << " (" << sptr << ") ";
+
+  if (rep->IsBtree()) {
+    const CordRepBtree* node = rep->btree();
+    std::string label =
+        node->height() ? absl::StrCat("Node(", node->height(), ")") : "Leaf";
+    stream << label << ", len = " << node->length
+           << ", begin = " << node->begin() << ", end = " << node->end()
+           << "\n";
+    for (CordRep* edge : node->Edges()) {
+      DumpAll(edge, include_contents, stream, depth + 1);
+    }
+  } else if (rep->tag == SUBSTRING) {
+    const CordRepSubstring* substring = rep->substring();
+    stream << "Substring, len = " << rep->length
+           << ", start = " << substring->start;
+    maybe_dump_data(rep);
+    DumpAll(substring->child, include_contents, stream, depth + 1);
+  } else if (rep->tag >= FLAT) {
+    stream << "Flat, len = " << rep->length;
+    maybe_dump_data(rep);
+  } else if (rep->tag == EXTERNAL) {
+    stream << "Extn, len = " << rep->length;
+    maybe_dump_data(rep);
+  }
+}
+
+// TODO(b/192061034): add 'bytes to copy' logic to avoid large slop on substring
+// small data out of large reps, and general efficiency of 'always copy small
+// data'. Consider making this a cord rep internal library function.
+CordRepSubstring* CreateSubstring(CordRep* rep, size_t offset, size_t n) {
+  assert(n != 0);
+  assert(offset + n <= rep->length);
+  assert(offset != 0 || n != rep->length);
+
+  if (rep->tag == SUBSTRING) {
+    CordRepSubstring* substring = rep->substring();
+    offset += substring->start;
+    rep = CordRep::Ref(substring->child);
+    CordRep::Unref(substring);
+  }
+  CordRepSubstring* substring = new CordRepSubstring();
+  substring->length = n;
+  substring->tag = SUBSTRING;
+  substring->start = offset;
+  substring->child = rep;
+  return substring;
+}
+
+// TODO(b/192061034): consider making this a cord rep library function.
+inline CordRep* MakeSubstring(CordRep* rep, size_t offset, size_t n) {
+  if (n == rep->length) return rep;
+  if (n == 0) return CordRep::Unref(rep), nullptr;
+  return CreateSubstring(rep, offset, n);
+}
+
+// TODO(b/192061034): consider making this a cord rep library function.
+inline CordRep* MakeSubstring(CordRep* rep, size_t offset) {
+  if (offset == 0) return rep;
+  return CreateSubstring(rep, offset, rep->length - offset);
+}
+
+template <EdgeType edge_type>
+inline absl::string_view Consume(absl::string_view s, size_t n) {
+  return edge_type == kBack ? s.substr(n) : s.substr(0, s.size() - n);
+}
+
+template <EdgeType edge_type>
+inline absl::string_view Consume(char* dst, absl::string_view s, size_t n) {
+  if (edge_type == kBack) {
+    memcpy(dst, s.data(), n);
+    return s.substr(n);
+  } else {
+    const size_t offset = s.size() - n;
+    memcpy(dst, s.data() + offset, n);
+    return s.substr(0, offset);
+  }
+}
+
+// Known issue / optimization weirdness: the store associated with the
+// decrement introduces traffic between cpus (even if the result of that
+// traffic does nothing), making this faster than a single call to
+// refcount.Decrement() checking the zero refcount condition.
+template <typename R, typename Fn>
+inline void FastUnref(R* r, Fn&& fn) {
+  if (r->refcount.IsOne()) {
+    fn(r);
+  } else if (!r->refcount.DecrementExpectHighRefcount()) {
+    fn(r);
+  }
+}
+
+// Deletes a leaf node data edge. Requires `rep` to be an EXTERNAL or FLAT
+// node, or a SUBSTRING of an EXTERNAL or FLAT node.
+void DeleteLeafEdge(CordRep* rep) {
+  for (;;) {
+    if (rep->tag >= FLAT) {
+      CordRepFlat::Delete(rep->flat());
+      return;
+    }
+    if (rep->tag == EXTERNAL) {
+      CordRepExternal::Delete(rep->external());
+      return;
+    }
+    assert(rep->tag == SUBSTRING);
+    CordRepSubstring* substring = rep->substring();
+    rep = substring->child;
+    assert(rep->tag == EXTERNAL || rep->tag >= FLAT);
+    delete substring;
+    if (rep->refcount.Decrement()) return;
+  }
+}
+
+// StackOperations contains the logic to build a left-most or right-most stack
+// (leg) down to the leaf level of a btree, and 'unwind' / 'Finalize' methods to
+// propagate node changes up the stack.
+template <EdgeType edge_type>
+struct StackOperations {
+  // Returns true if the node at 'depth' is not shared, i.e. has a refcount
+  // of one and all of its parent nodes have a refcount of one.
+  inline bool owned(int depth) const { return depth < share_depth; }
+
+  // Returns the node at 'depth'.
+  inline CordRepBtree* node(int depth) const { return stack[depth]; }
+
+  // Builds a `depth` levels deep stack starting at `tree` recording which nodes
+  // are private in the form of the 'share depth' where nodes are shared.
+  inline CordRepBtree* BuildStack(CordRepBtree* tree, int depth) {
+    assert(depth <= tree->height());
+    int current_depth = 0;
+    while (current_depth < depth && tree->refcount.IsOne()) {
+      stack[current_depth++] = tree;
+      tree = tree->Edge(edge_type)->btree();
+    }
+    share_depth = current_depth + (tree->refcount.IsOne() ? 1 : 0);
+    while (current_depth < depth) {
+      stack[current_depth++] = tree;
+      tree = tree->Edge(edge_type)->btree();
+    }
+    return tree;
+  }
+
+  // Builds a stack with the invariant that all nodes are private owned / not
+  // shared. This is used in iterative updates where a previous propagation
+  // guaranteed all nodes are owned / private.
+  inline void BuildOwnedStack(CordRepBtree* tree, int height) {
+    assert(height <= CordRepBtree::kMaxHeight);
+    int depth = 0;
+    while (depth < height) {
+      assert(tree->refcount.IsOne());
+      stack[depth++] = tree;
+      tree = tree->Edge(edge_type)->btree();
+    }
+    assert(tree->refcount.IsOne());
+    share_depth = depth + 1;
+  }
+
+  // Processes the final 'top level' result action for the tree.
+  // See the 'Action' enum for the various action implications.
+  static inline CordRepBtree* Finalize(CordRepBtree* tree, OpResult result) {
+    switch (result.action) {
+      case CordRepBtree::kPopped:
+        if (ABSL_PREDICT_FALSE(tree->height() >= CordRepBtree::kMaxHeight)) {
+          ABSL_RAW_LOG(FATAL, "Max height exceeded");
+        }
+        return edge_type == kBack ? CordRepBtree::New(tree, result.tree)
+                                  : CordRepBtree::New(result.tree, tree);
+      case CordRepBtree::kCopied:
+        CordRep::Unref(tree);
+        ABSL_FALLTHROUGH_INTENDED;
+      case CordRepBtree::kSelf:
+        return result.tree;
+    }
+    ABSL_INTERNAL_UNREACHABLE;
+    return result.tree;
+  }
+
+  // Propagate the action result in 'result' up into all nodes of the stack
+  // starting at depth 'depth'. 'length' contains the extra length of data that
+  // was added at the lowest level, and is updated into all nodes of the stack.
+  // See the 'Action' enum for the various action implications.
+  // If 'propagate' is true, then any copied node values are updated into the
+  // stack, which is used for iterative processing on the same stack.
+  template <bool propagate = false>
+  inline CordRepBtree* Unwind(CordRepBtree* tree, int depth, size_t length,
+                              OpResult result) {
+    // TODO(mvels): revisit the below code to check if 3 loops with 3
+    // (incremental) conditions is faster than 1 loop with a switch.
+    // Benchmarking and perf recordings indicate the loop with switch is
+    // fastest, likely because of indirect jumps on the tight case values and
+    // dense branches. But it's worth considering 3 loops, as the `action`
+    // transitions are mono directional. E.g.:
+    //   while (action == kPopped) {
+    //     ...
+    //   }
+    //   while (action == kCopied) {
+    //     ...
+    //   }
+    //   ...
+    // We also  found that an "if () do {}" loop here seems faster, possibly
+    // because it allows the branch predictor more granular heuristics on
+    // 'single leaf' (`depth` == 0) and 'single depth' (`depth` == 1) cases
+    // which appear to be the most common use cases.
+    if (depth != 0) {
+      do {
+        CordRepBtree* node = stack[--depth];
+        const bool owned = depth < share_depth;
+        switch (result.action) {
+          case CordRepBtree::kPopped:
+            assert(!propagate);
+            result = node->AddEdge<edge_type>(owned, result.tree, length);
+            break;
+          case CordRepBtree::kCopied:
+            result = node->SetEdge<edge_type>(owned, result.tree, length);
+            if (propagate) stack[depth] = result.tree;
+            break;
+          case CordRepBtree::kSelf:
+            node->length += length;
+            while (depth > 0) {
+              node = stack[--depth];
+              node->length += length;
+            }
+            return node;
+        }
+      } while (depth > 0);
+    }
+    return Finalize(tree, result);
+  }
+
+  // Invokes `Unwind` with `propagate=true` to update the stack node values.
+  inline CordRepBtree* Propagate(CordRepBtree* tree, int depth, size_t length,
+                                 OpResult result) {
+    return Unwind</*propagate=*/true>(tree, depth, length, result);
+  }
+
+  // `share_depth` contains the depth at which the nodes in the stack become
+  // shared. I.e., if the top most level is shared (i.e.: `!refcount.IsOne()`),
+  // then `share_depth` is 0. If the 2nd node is shared (and implicitly all
+  // nodes below that) then `share_depth` is 1, etc. A `share_depth` greater
+  // than the depth of the stack indicates that none of the nodes in the stack
+  // are shared.
+  int share_depth;
+
+  NodeStack stack;
+};
+
+}  // namespace
+
+void CordRepBtree::Dump(const CordRep* rep, absl::string_view label,
+                        bool include_contents, std::ostream& stream) {
+  stream << "===================================\n";
+  if (!label.empty()) {
+    stream << label << '\n';
+    stream << "-----------------------------------\n";
+  }
+  if (rep) {
+    DumpAll(rep, include_contents, stream);
+  } else {
+    stream << "NULL\n";
+  }
+}
+
+void CordRepBtree::Dump(const CordRep* rep, absl::string_view label,
+                        std::ostream& stream) {
+  Dump(rep, label, false, stream);
+}
+
+void CordRepBtree::Dump(const CordRep* rep, std::ostream& stream) {
+  Dump(rep, absl::string_view(), false, stream);
+}
+
+void CordRepBtree::DestroyLeaf(CordRepBtree* tree, size_t begin, size_t end) {
+  for (CordRep* edge : tree->Edges(begin, end)) {
+    FastUnref(edge, DeleteLeafEdge);
+  }
+  Delete(tree);
+}
+
+void CordRepBtree::DestroyNonLeaf(CordRepBtree* tree, size_t begin,
+                                  size_t end) {
+  for (CordRep* edge : tree->Edges(begin, end)) {
+    FastUnref(edge->btree(), Destroy);
+  }
+  Delete(tree);
+}
+
+bool CordRepBtree::IsValid(const CordRepBtree* tree, bool shallow) {
+#define NODE_CHECK_VALID(x)                                           \
+  if (!(x)) {                                                         \
+    ABSL_RAW_LOG(ERROR, "CordRepBtree::CheckValid() FAILED: %s", #x); \
+    return false;                                                     \
+  }
+#define NODE_CHECK_EQ(x, y)                                                    \
+  if ((x) != (y)) {                                                            \
+    ABSL_RAW_LOG(ERROR,                                                        \
+                 "CordRepBtree::CheckValid() FAILED: %s != %s (%s vs %s)", #x, \
+                 #y, absl::StrCat(x).c_str(), absl::StrCat(y).c_str());        \
+    return false;                                                              \
+  }
+
+  NODE_CHECK_VALID(tree != nullptr);
+  NODE_CHECK_VALID(tree->IsBtree());
+  NODE_CHECK_VALID(tree->height() <= kMaxHeight);
+  NODE_CHECK_VALID(tree->begin() < tree->capacity());
+  NODE_CHECK_VALID(tree->end() <= tree->capacity());
+  NODE_CHECK_VALID(tree->begin() <= tree->end());
+  size_t child_length = 0;
+  for (CordRep* edge : tree->Edges()) {
+    NODE_CHECK_VALID(edge != nullptr);
+    if (tree->height() > 0) {
+      NODE_CHECK_VALID(edge->IsBtree());
+      NODE_CHECK_VALID(edge->btree()->height() == tree->height() - 1);
+    } else {
+      NODE_CHECK_VALID(IsDataEdge(edge));
+    }
+    child_length += edge->length;
+  }
+  NODE_CHECK_EQ(child_length, tree->length);
+  if ((!shallow || exhaustive_validation()) && tree->height() > 0) {
+    for (CordRep* edge : tree->Edges()) {
+      if (!IsValid(edge->btree(), shallow)) return false;
+    }
+  }
+  return true;
+
+#undef NODE_CHECK_VALID
+#undef NODE_CHECK_EQ
+}
+
+#ifndef NDEBUG
+
+CordRepBtree* CordRepBtree::AssertValid(CordRepBtree* tree, bool shallow) {
+  if (!IsValid(tree, shallow)) {
+    Dump(tree, "CordRepBtree validation failed:", false, std::cout);
+    ABSL_RAW_LOG(FATAL, "CordRepBtree::CheckValid() FAILED");
+  }
+  return tree;
+}
+
+const CordRepBtree* CordRepBtree::AssertValid(const CordRepBtree* tree,
+                                              bool shallow) {
+  if (!IsValid(tree, shallow)) {
+    Dump(tree, "CordRepBtree validation failed:", false, std::cout);
+    ABSL_RAW_LOG(FATAL, "CordRepBtree::CheckValid() FAILED");
+  }
+  return tree;
+}
+
+#endif  // NDEBUG
+
+template <EdgeType edge_type>
+inline OpResult CordRepBtree::AddEdge(bool owned, CordRep* edge, size_t delta) {
+  if (size() >= kMaxCapacity) return {New(edge), kPopped};
+  OpResult result = ToOpResult(owned);
+  result.tree->Add<edge_type>(edge);
+  result.tree->length += delta;
+  return result;
+}
+
+template <EdgeType edge_type>
+OpResult CordRepBtree::SetEdge(bool owned, CordRep* edge, size_t delta) {
+  OpResult result;
+  const size_t idx = index(edge_type);
+  if (owned) {
+    result = {this, kSelf};
+    CordRep::Unref(edges_[idx]);
+  } else {
+    // Create a copy containing all unchanged edges. Unchanged edges are the
+    // open interval [begin, back) or [begin + 1, end) depending on `edge_type`.
+    // We conveniently cover both case using a constexpr `shift` being 0 or 1
+    // as `end :== back + 1`.
+    result = {CopyRaw(), kCopied};
+    constexpr int shift = edge_type == kFront ? 1 : 0;
+    for (CordRep* r : Edges(begin() + shift, back() + shift)) {
+      CordRep::Ref(r);
+    }
+  }
+  result.tree->edges_[idx] = edge;
+  result.tree->length += delta;
+  return result;
+}
+
+template <EdgeType edge_type>
+CordRepBtree* CordRepBtree::AddCordRep(CordRepBtree* tree, CordRep* rep) {
+  const int depth = tree->height();
+  const size_t length = rep->length;
+  StackOperations<edge_type> ops;
+  CordRepBtree* leaf = ops.BuildStack(tree, depth);
+  const OpResult result =
+      leaf->AddEdge<edge_type>(ops.owned(depth), rep, length);
+  return ops.Unwind(tree, depth, length, result);
+}
+
+template <>
+CordRepBtree* CordRepBtree::NewLeaf<kBack>(absl::string_view data,
+                                           size_t extra) {
+  CordRepBtree* leaf = CordRepBtree::New(0);
+  size_t length = 0;
+  size_t end = 0;
+  const size_t cap = leaf->capacity();
+  while (!data.empty() && end != cap) {
+    auto* flat = CordRepFlat::New(data.length() + extra);
+    flat->length = (std::min)(data.length(), flat->Capacity());
+    length += flat->length;
+    leaf->edges_[end++] = flat;
+    data = Consume<kBack>(flat->Data(), data, flat->length);
+  }
+  leaf->length = length;
+  leaf->set_end(end);
+  return leaf;
+}
+
+template <>
+CordRepBtree* CordRepBtree::NewLeaf<kFront>(absl::string_view data,
+                                            size_t extra) {
+  CordRepBtree* leaf = CordRepBtree::New(0);
+  size_t length = 0;
+  size_t begin = leaf->capacity();
+  leaf->set_end(leaf->capacity());
+  while (!data.empty() && begin != 0) {
+    auto* flat = CordRepFlat::New(data.length() + extra);
+    flat->length = (std::min)(data.length(), flat->Capacity());
+    length += flat->length;
+    leaf->edges_[--begin] = flat;
+    data = Consume<kFront>(flat->Data(), data, flat->length);
+  }
+  leaf->length = length;
+  leaf->set_begin(begin);
+  return leaf;
+}
+
+template <>
+absl::string_view CordRepBtree::AddData<kBack>(absl::string_view data,
+                                               size_t extra) {
+  assert(!data.empty());
+  assert(size() < capacity());
+  AlignBegin();
+  const size_t cap = capacity();
+  do {
+    CordRepFlat* flat = CordRepFlat::New(data.length() + extra);
+    const size_t n = (std::min)(data.length(), flat->Capacity());
+    flat->length = n;
+    edges_[fetch_add_end(1)] = flat;
+    data = Consume<kBack>(flat->Data(), data, n);
+  } while (!data.empty() && end() != cap);
+  return data;
+}
+
+template <>
+absl::string_view CordRepBtree::AddData<kFront>(absl::string_view data,
+                                                size_t extra) {
+  assert(!data.empty());
+  assert(size() < capacity());
+  AlignEnd();
+  do {
+    CordRepFlat* flat = CordRepFlat::New(data.length() + extra);
+    const size_t n = (std::min)(data.length(), flat->Capacity());
+    flat->length = n;
+    edges_[sub_fetch_begin(1)] = flat;
+    data = Consume<kFront>(flat->Data(), data, n);
+  } while (!data.empty() && begin() != 0);
+  return data;
+}
+
+template <EdgeType edge_type>
+CordRepBtree* CordRepBtree::AddData(CordRepBtree* tree, absl::string_view data,
+                                    size_t extra) {
+  if (ABSL_PREDICT_FALSE(data.empty())) return tree;
+
+  const size_t original_data_size = data.size();
+  int depth = tree->height();
+  StackOperations<edge_type> ops;
+  CordRepBtree* leaf = ops.BuildStack(tree, depth);
+
+  // If there is capacity in the last edge, append as much data
+  // as possible into this last edge.
+  if (leaf->size() < leaf->capacity()) {
+    OpResult result = leaf->ToOpResult(ops.owned(depth));
+    data = result.tree->AddData<edge_type>(data, extra);
+    if (data.empty()) {
+      result.tree->length += original_data_size;
+      return ops.Unwind(tree, depth, original_data_size, result);
+    }
+
+    // We added some data into this leaf, but not all. Propagate the added
+    // length to the top most node, and rebuild the stack with any newly copied
+    // or updated nodes. From this point on, the path (leg) from the top most
+    // node to the right-most node towards the leaf node is privately owned.
+    size_t delta = original_data_size - data.size();
+    assert(delta > 0);
+    result.tree->length += delta;
+    tree = ops.Propagate(tree, depth, delta, result);
+    ops.share_depth = depth + 1;
+  }
+
+  // We were unable to append all data into the existing right-most leaf node.
+  // This means all remaining data must be put into (a) new leaf node(s) which
+  // we append to the tree. To make this efficient, we iteratively build full
+  // leaf nodes from `data` until the created leaf contains all remaining data.
+  // We utilize the `Unwind` method to merge the created leaf into the first
+  // level towards root that has capacity. On each iteration with remaining
+  // data, we rebuild the stack in the knowledge that right-most nodes are
+  // privately owned after the first `Unwind` completes.
+  for (;;) {
+    OpResult result = {CordRepBtree::NewLeaf<edge_type>(data, extra), kPopped};
+    if (result.tree->length == data.size()) {
+      return ops.Unwind(tree, depth, result.tree->length, result);
+    }
+    data = Consume<edge_type>(data, result.tree->length);
+    tree = ops.Unwind(tree, depth, result.tree->length, result);
+    depth = tree->height();
+    ops.BuildOwnedStack(tree, depth);
+  }
+}
+
+template <EdgeType edge_type>
+CordRepBtree* CordRepBtree::Merge(CordRepBtree* dst, CordRepBtree* src) {
+  assert(dst->height() >= src->height());
+
+  // Capture source length as we may consume / destroy `src`.
+  const size_t length = src->length;
+
+  // We attempt to merge `src` at its corresponding height in `dst`.
+  const int depth = dst->height() - src->height();
+  StackOperations<edge_type> ops;
+  CordRepBtree* merge_node = ops.BuildStack(dst, depth);
+
+  // If there is enough space in `merge_node` for all edges from `src`, add all
+  // edges to this node, making a fresh copy as needed if not privately owned.
+  // If `merge_node` does not have capacity for `src`, we rely on `Unwind` and
+  // `Finalize` to merge `src` into the first level towards `root` where there
+  // is capacity for another edge, or create a new top level node.
+  OpResult result;
+  if (merge_node->size() + src->size() <= kMaxCapacity) {
+    result = merge_node->ToOpResult(ops.owned(depth));
+    result.tree->Add<edge_type>(src->Edges());
+    result.tree->length += src->length;
+    if (src->refcount.IsOne()) {
+      Delete(src);
+    } else {
+      for (CordRep* edge : src->Edges()) CordRep::Ref(edge);
+      CordRepBtree::Unref(src);
+    }
+  } else {
+    result = {src, kPopped};
+  }
+
+  // Unless we merged at the top level (i.e.: src and dst are equal height),
+  // unwind the result towards the top level, and finalize the result.
+  if (depth) {
+    return ops.Unwind(dst, depth, length, result);
+  }
+  return ops.Finalize(dst, result);
+}
+
+CopyResult CordRepBtree::CopySuffix(size_t offset) {
+  assert(offset < this->length);
+
+  // As long as `offset` starts inside the last edge, we can 'drop' the current
+  // depth. For the most extreme example: if offset references the last data
+  // edge in the tree, there is only a single edge / path from the top of the
+  // tree to that last edge, so we can drop all the nodes except that edge.
+  // The fast path check for this is `back->length >= length - offset`.
+  int height = this->height();
+  CordRepBtree* node = this;
+  size_t len = node->length - offset;
+  CordRep* back = node->Edge(kBack);
+  while (back->length >= len) {
+    offset = back->length - len;
+    if (--height < 0) {
+      return {MakeSubstring(CordRep::Ref(back), offset), height};
+    }
+    node = back->btree();
+    back = node->Edge(kBack);
+  }
+  if (offset == 0) return {CordRep::Ref(node), height};
+
+  // Offset does not point into the last edge, so we span at least two edges.
+  // Find the index of offset with `IndexBeyond` which provides us the edge
+  // 'beyond' the offset if offset is not a clean starting point of an edge.
+  Position pos = node->IndexBeyond(offset);
+  CordRepBtree* sub = node->CopyToEndFrom(pos.index, len);
+  const CopyResult result = {sub, height};
+
+  // `pos.n` contains a non zero value if the offset is not an exact starting
+  // point of an edge. In this case, `pos.n` contains the 'trailing' amount of
+  // bytes of the edge preceding that in `pos.index`. We need to iteratively
+  // adjust the preceding edge with the 'broken' offset until we have a perfect
+  // start of the edge.
+  while (pos.n != 0) {
+    assert(pos.index >= 1);
+    const size_t begin = pos.index - 1;
+    sub->set_begin(begin);
+    CordRep* const edge = node->Edge(begin);
+
+    len = pos.n;
+    offset = edge->length - len;
+
+    if (--height < 0) {
+      sub->edges_[begin] = MakeSubstring(CordRep::Ref(edge), offset, len);
+      return result;
+    }
+
+    node = edge->btree();
+    pos = node->IndexBeyond(offset);
+
+    CordRepBtree* nsub = node->CopyToEndFrom(pos.index, len);
+    sub->edges_[begin] = nsub;
+    sub = nsub;
+  }
+  sub->set_begin(pos.index);
+  return result;
+}
+
+CopyResult CordRepBtree::CopyPrefix(size_t n) {
+  assert(n > 0);
+  assert(n <= this->length);
+
+  // As long as `n` does not exceed the length of the first edge, we can 'drop'
+  // the current depth. For the most extreme example: if we'd copy a 1 byte
+  // prefix from a tree, there is only a single edge / path from the top of the
+  // tree to the single data edge containing this byte, so we can drop all the
+  // nodes except the data node.
+  int height = this->height();
+  CordRepBtree* node = this;
+  CordRep* front = node->Edge(kFront);
+  while (front->length >= n) {
+    if (--height < 0) return {MakeSubstring(CordRep::Ref(front), 0, n), -1};
+    node = front->btree();
+    front = node->Edge(kFront);
+  }
+  if (node->length == n) return {CordRep::Ref(node), height};
+
+  // `n` spans at least two nodes, find the end point of the span.
+  Position pos = node->IndexOf(n);
+
+  // Create a partial copy of the node up to `pos.index`, with a defined length
+  // of `n`. Any 'partial last edge' is added further below as needed.
+  CordRepBtree* sub = node->CopyBeginTo(pos.index, n);
+  const CopyResult result = {sub, height};
+
+  // `pos.n` contains the 'offset inside the edge for IndexOf(n)'. As long as
+  // this is not zero, we don't have a 'clean cut', so we need to make a
+  // (partial) copy of that last edge, and repeat this until pos.n is zero.
+  while (pos.n != 0) {
+    size_t end = pos.index;
+    n = pos.n;
+
+    CordRep* edge = node->Edge(pos.index);
+    if (--height < 0) {
+      sub->edges_[end++] = MakeSubstring(CordRep::Ref(edge), 0, n);
+      sub->set_end(end);
+      AssertValid(result.edge->btree());
+      return result;
+    }
+
+    node = edge->btree();
+    pos = node->IndexOf(n);
+    CordRepBtree* nsub = node->CopyBeginTo(pos.index, n);
+    sub->edges_[end++] = nsub;
+    sub->set_end(end);
+    sub = nsub;
+  }
+  sub->set_end(pos.index);
+  AssertValid(result.edge->btree());
+  return result;
+}
+
+CordRep* CordRepBtree::SubTree(size_t offset, size_t n) {
+  assert(n <= this->length);
+  assert(offset <= this->length - n);
+  if (ABSL_PREDICT_FALSE(n == 0)) return nullptr;
+
+  CordRepBtree* node = this;
+  int height = node->height();
+  Position front = node->IndexOf(offset);
+  CordRep* left = node->edges_[front.index];
+  while (front.n + n <= left->length) {
+    if (--height < 0) return MakeSubstring(CordRep::Ref(left), front.n, n);
+    node = left->btree();
+    front = node->IndexOf(front.n);
+    left = node->edges_[front.index];
+  }
+
+  const Position back = node->IndexBefore(front, n);
+  CordRep* const right = node->edges_[back.index];
+  assert(back.index > front.index);
+
+  // Get partial suffix and prefix entries.
+  CopyResult prefix;
+  CopyResult suffix;
+  if (height > 0) {
+    // Copy prefix and suffix of the boundary nodes.
+    prefix = left->btree()->CopySuffix(front.n);
+    suffix = right->btree()->CopyPrefix(back.n);
+
+    // If there is an edge between the prefix and suffix edges, then the tree
+    // must remain at its previous (full) height. If we have no edges between
+    // prefix and suffix edges, then the tree must be as high as either the
+    // suffix or prefix edges (which are collapsed to their minimum heights).
+    if (front.index + 1 == back.index) {
+      height = (std::max)(prefix.height, suffix.height) + 1;
+    }
+
+    // Raise prefix and suffixes to the new tree height.
+    for (int h = prefix.height + 1; h < height; ++h) {
+      prefix.edge = CordRepBtree::New(prefix.edge);
+    }
+    for (int h = suffix.height + 1; h < height; ++h) {
+      suffix.edge = CordRepBtree::New(suffix.edge);
+    }
+  } else {
+    // Leaf node, simply take substrings for prefix and suffix.
+    prefix = CopyResult{MakeSubstring(CordRep::Ref(left), front.n), -1};
+    suffix = CopyResult{MakeSubstring(CordRep::Ref(right), 0, back.n), -1};
+  }
+
+  // Compose resulting tree.
+  CordRepBtree* sub = CordRepBtree::New(height);
+  size_t end = 0;
+  sub->edges_[end++] = prefix.edge;
+  for (CordRep* r : node->Edges(front.index + 1, back.index)) {
+    sub->edges_[end++] = CordRep::Ref(r);
+  }
+  sub->edges_[end++] = suffix.edge;
+  sub->set_end(end);
+  sub->length = n;
+  return AssertValid(sub);
+}
+
+CordRepBtree* CordRepBtree::MergeTrees(CordRepBtree* left,
+                                       CordRepBtree* right) {
+  return left->height() >= right->height() ? Merge<kBack>(left, right)
+                                           : Merge<kFront>(right, left);
+}
+
+bool CordRepBtree::IsFlat(absl::string_view* fragment) const {
+  if (height() == 0 && size() == 1) {
+    if (fragment) *fragment = Data(begin());
+    return true;
+  }
+  return false;
+}
+
+bool CordRepBtree::IsFlat(size_t offset, const size_t n,
+                          absl::string_view* fragment) const {
+  assert(n <= this->length);
+  assert(offset <= this->length - n);
+  if (ABSL_PREDICT_FALSE(n == 0)) return false;
+  int height = this->height();
+  const CordRepBtree* node = this;
+  for (;;) {
+    const Position front = node->IndexOf(offset);
+    const CordRep* edge = node->Edge(front.index);
+    if (edge->length < front.n + n) return false;
+    if (--height < 0) {
+      if (fragment) *fragment = EdgeData(edge).substr(front.n, n);
+      return true;
+    }
+    offset = front.n;
+    node = node->Edge(front.index)->btree();
+  }
+}
+
+char CordRepBtree::GetCharacter(size_t offset) const {
+  assert(offset < length);
+  const CordRepBtree* node = this;
+  int height = node->height();
+  for (;;) {
+    Position front = node->IndexOf(offset);
+    if (--height < 0) return node->Data(front.index)[front.n];
+    offset = front.n;
+    node = node->Edge(front.index)->btree();
+  }
+}
+
+Span<char> CordRepBtree::GetAppendBufferSlow(size_t size) {
+  // The inlined version in `GetAppendBuffer()` deals with all heights <= 3.
+  assert(height() >= 4);
+  assert(refcount.IsOne());
+
+  // Build a stack of nodes we may potentially need to update if we find a
+  // non-shared FLAT with capacity at the leaf level.
+  const int depth = height();
+  CordRepBtree* node = this;
+  CordRepBtree* stack[kMaxDepth];
+  for (int i = 0; i < depth; ++i) {
+    node = node->Edge(kBack)->btree();
+    if (!node->refcount.IsOne()) return {};
+    stack[i] = node;
+  }
+
+  // Must be a privately owned flat.
+  CordRep* const edge = node->Edge(kBack);
+  if (!edge->refcount.IsOne() || edge->tag < FLAT) return {};
+
+  // Must have capacity.
+  const size_t avail = edge->flat()->Capacity() - edge->length;
+  if (avail == 0) return {};
+
+  // Build span on remaining capacity.
+  size_t delta = (std::min)(size, avail);
+  Span<char> span = {edge->flat()->Data() + edge->length, delta};
+  edge->length += delta;
+  this->length += delta;
+  for (int i = 0; i < depth; ++i) {
+    stack[i]->length += delta;
+  }
+  return span;
+}
+
+CordRepBtree* CordRepBtree::CreateSlow(CordRep* rep) {
+  if (rep->IsBtree()) return rep->btree();
+
+  CordRepBtree* node = nullptr;
+  auto consume = [&node](CordRep* r, size_t offset, size_t length) {
+    r = MakeSubstring(r, offset, length);
+    if (node == nullptr) {
+      node = New(r);
+    } else {
+      node = CordRepBtree::AddCordRep<kBack>(node, r);
+    }
+  };
+  Consume(rep, consume);
+  return node;
+}
+
+CordRepBtree* CordRepBtree::AppendSlow(CordRepBtree* tree, CordRep* rep) {
+  if (ABSL_PREDICT_TRUE(rep->IsBtree())) {
+    return MergeTrees(tree, rep->btree());
+  }
+  auto consume = [&tree](CordRep* r, size_t offset, size_t length) {
+    r = MakeSubstring(r, offset, length);
+    tree = CordRepBtree::AddCordRep<kBack>(tree, r);
+  };
+  Consume(rep, consume);
+  return tree;
+}
+
+CordRepBtree* CordRepBtree::PrependSlow(CordRepBtree* tree, CordRep* rep) {
+  if (ABSL_PREDICT_TRUE(rep->IsBtree())) {
+    return MergeTrees(rep->btree(), tree);
+  }
+  auto consume = [&tree](CordRep* r, size_t offset, size_t length) {
+    r = MakeSubstring(r, offset, length);
+    tree = CordRepBtree::AddCordRep<kFront>(tree, r);
+  };
+  ReverseConsume(rep, consume);
+  return tree;
+}
+
+CordRepBtree* CordRepBtree::Append(CordRepBtree* tree, absl::string_view data,
+                                   size_t extra) {
+  return CordRepBtree::AddData<kBack>(tree, data, extra);
+}
+
+CordRepBtree* CordRepBtree::Prepend(CordRepBtree* tree, absl::string_view data,
+                                    size_t extra) {
+  return CordRepBtree::AddData<kFront>(tree, data, extra);
+}
+
+template CordRepBtree* CordRepBtree::AddCordRep<kFront>(CordRepBtree* tree,
+                                                        CordRep* rep);
+template CordRepBtree* CordRepBtree::AddCordRep<kBack>(CordRepBtree* tree,
+                                                       CordRep* rep);
+template CordRepBtree* CordRepBtree::AddData<kFront>(CordRepBtree* tree,
+                                                     absl::string_view data,
+                                                     size_t extra);
+template CordRepBtree* CordRepBtree::AddData<kBack>(CordRepBtree* tree,
+                                                    absl::string_view data,
+                                                    size_t extra);
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.h
new file mode 100644
index 00000000000..8f000cab698
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree.h
@@ -0,0 +1,871 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_H_
+#define ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_H_
+
+#include <cassert>
+#include <cstdint>
+#include <iosfwd>
+
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/base/optimization.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+#include "absl/strings/string_view.h"
+#include "absl/types/span.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+class CordRepBtreeNavigator;
+
+// CordRepBtree is as the name implies a btree implementation of a Cordrep tree.
+// Data is stored at the leaf level only, non leaf nodes contain down pointers
+// only. Allowed types of data edges are FLAT, EXTERNAL and SUBSTRINGs of FLAT
+// or EXTERNAL nodes. The implementation allows for data to be added to either
+// end of the tree only, it does not provide any 'insert' logic. This has the
+// benefit that we can expect good fill ratios: all nodes except the outer
+// 'legs' will have 100% fill ratios for trees built using Append/Prepend
+// methods. Merged trees will typically have a fill ratio well above 50% as in a
+// similar fashion, one side of the merged tree will typically have a 100% fill
+// ratio, and the 'open' end will average 50%. All operations are O(log(n)) or
+// better, and the tree never needs balancing.
+//
+// All methods accepting a CordRep* or CordRepBtree* adopt a reference on that
+// input unless explicitly stated otherwise. All functions returning a CordRep*
+// or CordRepBtree* instance transfer a reference back to the caller.
+// Simplified, callers both 'donate' and 'consume' a reference count on each
+// call, simplifying the API. An example of building a tree:
+//
+//   CordRepBtree* tree = CordRepBtree::Create(MakeFlat("Hello"));
+//   tree = CordRepBtree::Append(tree, MakeFlat("world"));
+//
+// In the above example, all inputs are consumed, making each call affecting
+// `tree` reference count neutral. The returned `tree` value can be different
+// from the input if the input is shared with other threads, or if the tree
+// grows in height, but callers typically never have to concern themselves with
+// that and trust that all methods DTRT at all times.
+class CordRepBtree : public CordRep {
+ public:
+  // EdgeType identifies `front` and `back` enum values.
+  // Various implementations in CordRepBtree such as `Add` and `Edge` are
+  // generic and templated on operating on either of the boundary edges.
+  // For more information on the possible edges contained in a CordRepBtree
+  // instance see the documentation for `edges_`.
+  enum class EdgeType { kFront, kBack };
+
+  // Convenience constants into `EdgeType`
+  static constexpr EdgeType kFront = EdgeType::kFront;
+  static constexpr EdgeType kBack = EdgeType::kBack;
+
+  // Maximum number of edges: based on experiments and performance data, we can
+  // pick suitable values resulting in optimum cacheline aligned values. The
+  // preferred values are based on 64-bit systems where we aim to align this
+  // class onto 64 bytes, i.e.:  6 = 64 bytes, 14 = 128 bytes, etc.
+  // TODO(b/192061034): experiment with alternative sizes.
+  static constexpr size_t kMaxCapacity = 6;
+
+  // Reasonable maximum height of the btree. We can expect a fill ratio of at
+  // least 50%: trees are always expanded at the front or back. Concatenating
+  // trees will then typically fold at the top most node, where the lower nodes
+  // are at least at capacity on one side of joined inputs. At a lower fill
+  // rate of 4 edges per node, we have capacity for ~16 million leaf nodes.
+  // We will fail / abort if an application ever exceeds this height, which
+  // should be extremely rare (near impossible) and be an indication of an
+  // application error: we do not assume it reasonable for any application to
+  // operate correctly with such monster trees.
+  // Another compelling reason for the number `12` is that any contextual stack
+  // required for navigation or insertion requires 12 words and 12 bytes, which
+  // fits inside 2 cache lines with some room to spare, and is reasonable as a
+  // local stack variable compared to Cord's current near 400 bytes stack use.
+  // The maximum `height` value of a node is then `kMaxDepth - 1` as node height
+  // values start with a value of 0 for leaf nodes.
+  static constexpr int kMaxDepth = 12;
+  static constexpr int kMaxHeight = kMaxDepth - 1;
+
+  // `Action` defines the action for unwinding changes done at the btree's leaf
+  // level that need to be propagated up to the parent node(s). Each operation
+  // on a node has an effect / action defined as follows:
+  // - kSelf
+  //   The operation (add / update, etc) was performed directly on the node as
+  //   the node is private to the current thread (i.e.: not shared directly or
+  //   indirectly through a refcount > 1). Changes can be propagated directly to
+  //   all parent nodes as all parent nodes are also then private to the current
+  //   thread.
+  // - kCopied
+  //   The operation (add / update, etc) was performed on a copy of the original
+  //   node, as the node is (potentially) directly or indirectly shared with
+  //   other threads. Changes need to be propagated into the parent nodes where
+  //   the old down pointer must be unreffed and replaced with this new copy.
+  //   Such changes to parent nodes may themselves require a copy if the parent
+  //   node is also shared. A kCopied action can propagate all the way to the
+  //   top node where we then must unref the `tree` input provided by the
+  //   caller, and return the new copy.
+  // - kPopped
+  //   The operation (typically add) could not be satisfied due to insufficient
+  //   capacity in the targeted node, and a new 'leg' was created that needs to
+  //   be added into the parent node. For example, adding a FLAT inside a leaf
+  //   node that is at capacity will create a new leaf node containing that
+  //   FLAT, that needs to be 'popped' up the btree. Such 'pop' actions can
+  //   cascade up the tree if parent nodes are also at capacity. A 'Popped'
+  //   action propagating all the way to the top of the tree will result in
+  //   the tree becoming one level higher than the current tree through a final
+  //   `CordRepBtree::New(tree, popped)` call, resulting in a new top node
+  //   referencing the old tree and the new (fully popped upwards) 'leg'.
+  enum Action { kSelf, kCopied, kPopped };
+
+  // Result of an operation on a node. See the `Action` enum for details.
+  struct OpResult {
+    CordRepBtree* tree;
+    Action action;
+  };
+
+  // Return value of the CopyPrefix and CopySuffix methods which can
+  // return a node or data edge at any height inside the tree.
+  // A height of 0 defines the lowest (leaf) node, a height of -1 identifies
+  // `edge` as being a plain data node: EXTERNAL / FLAT or SUBSTRING thereof.
+  struct CopyResult {
+    CordRep* edge;
+    int height;
+  };
+
+  // Logical position inside a node:
+  // - index: index of the edge.
+  // - n: size or offset value depending on context.
+  struct Position {
+    size_t index;
+    size_t n;
+  };
+
+  // Creates a btree from the given input. Adopts a ref of `rep`.
+  // If the input `rep` is itself a btree, i.e., `IsBtree()`, then this
+  // function immediately returns `rep->btree()`. If the input is a valid data
+  // edge (see IsDataEdge()), then a new leaf node is returned containing `rep`
+  // as the sole data edge. Else, the input is assumed to be a (legacy) concat
+  // tree, and the input is consumed and transformed into a btree().
+  static CordRepBtree* Create(CordRep* rep);
+
+  // Destroys the provided tree. Should only be called by cord internal API's,
+  // typically after a ref_count.Decrement() on the last reference count.
+  static void Destroy(CordRepBtree* tree);
+
+  // Appends / Prepends an existing CordRep instance to this tree.
+  // The below methods accept three types of input:
+  // 1) `rep` is a data node (See `IsDataNode` for valid data edges).
+  // `rep` is appended or prepended to this tree 'as is'.
+  // 2) `rep` is a BTREE.
+  // `rep` is merged into `tree` respecting the Append/Prepend order.
+  // 3) `rep` is some other (legacy) type.
+  // `rep` is converted in place and added to `tree`
+  // Requires `tree` and `rep` to be not null.
+  static CordRepBtree* Append(CordRepBtree* tree, CordRep* rep);
+  static CordRepBtree* Prepend(CordRepBtree* tree, CordRep* rep);
+
+  // Append/Prepend the data in `data` to this tree.
+  // The `extra` parameter defines how much extra capacity should be allocated
+  // for any additional FLAT being allocated. This is an optimization hint from
+  // the caller. For example, a caller may need to add 2 string_views of data
+  // "abc" and "defghi" which are not consecutive. The caller can in this case
+  // invoke `AddData(tree, "abc", 6)`, and any newly added flat is allocated
+  // where possible with at least 6 bytes of extra capacity beyond `length`.
+  // This helps avoiding data getting fragmented over multiple flats.
+  // There is no limit on the size of `data`. If `data` can not be stored inside
+  // a single flat, then the function will iteratively add flats until all data
+  // has been consumed and appended or prepended to the tree.
+  static CordRepBtree* Append(CordRepBtree* tree, string_view data,
+                              size_t extra = 0);
+  static CordRepBtree* Prepend(CordRepBtree* tree, string_view data,
+                               size_t extra = 0);
+
+  // Returns a new tree, containing `n` bytes of data from this instance
+  // starting at offset `offset`. Where possible, the returned tree shares
+  // (re-uses) data edges and nodes with this instance to minimize the
+  // combined memory footprint of both trees.
+  // Requires `offset + n <= length`. Returns `nullptr` if `n` is zero.
+  CordRep* SubTree(size_t offset, size_t n);
+
+  // Returns the character at the given offset.
+  char GetCharacter(size_t offset) const;
+
+  // Returns true if this node holds a single data edge, and if so, sets
+  // `fragment` to reference the contained data. `fragment` is an optional
+  // output parameter and allowed to be null.
+  bool IsFlat(absl::string_view* fragment) const;
+
+  // Returns true if the data of `n` bytes starting at offset `offset`
+  // is contained in a single data edge, and if so, sets fragment to reference
+  // the contained data. `fragment` is an optional output parameter and allowed
+  // to be null.
+  bool IsFlat(size_t offset, size_t n, absl::string_view* fragment) const;
+
+  // Returns a span (mutable range of bytes) of up to `size` bytes into the
+  // last FLAT data edge inside this tree under the following conditions:
+  // - none of the nodes down into the FLAT node are shared.
+  // - the last data edge in this tree is a non-shared FLAT.
+  // - the referenced FLAT has additional capacity available.
+  // If all these conditions are met, a non-empty span is returned, and the
+  // length of the flat node and involved tree nodes have been increased by
+  // `span.length()`. The caller is responsible for immediately assigning values
+  // to all uninitialized data reference by the returned span.
+  // Requires `this->refcount.IsOne()`: this function forces the caller to do
+  // this fast path check on the top level node, as this is the most commonly
+  // shared node of a cord tree.
+  Span<char> GetAppendBuffer(size_t size);
+
+  // Returns the `height` of the tree. The height of a tree is limited to
+  // kMaxHeight. `height` is implemented as an `int` as in some places we
+  // use negative (-1) values for 'data edges'.
+  int height() const { return static_cast<int>(storage[0]); }
+
+  // Properties: begin, back, end, front/back boundary indexes.
+  size_t begin() const { return static_cast<size_t>(storage[1]); }
+  size_t back() const { return static_cast<size_t>(storage[2]) - 1; }
+  size_t end() const { return static_cast<size_t>(storage[2]); }
+  size_t index(EdgeType edge) const {
+    return edge == kFront ? begin() : back();
+  }
+
+  // Properties: size and capacity.
+  // `capacity` contains the current capacity of this instance, where
+  // `kMaxCapacity` contains the maximum capacity of a btree node.
+  // For now, `capacity` and `kMaxCapacity` return the same value, but this may
+  // change in the future if we see benefit in dynamically sizing 'small' nodes
+  // to 'large' nodes for large data trees.
+  size_t size() const { return end() - begin(); }
+  size_t capacity() const { return kMaxCapacity; }
+
+  // Edge access
+  inline CordRep* Edge(size_t index) const;
+  inline CordRep* Edge(EdgeType edge_type) const;
+  inline absl::Span<CordRep* const> Edges() const;
+  inline absl::Span<CordRep* const> Edges(size_t begin, size_t end) const;
+
+  // Returns reference to the data edge at `index`.
+  // Requires this instance to be a leaf node, and `index` to be valid index.
+  inline absl::string_view Data(size_t index) const;
+
+  static const char* EdgeDataPtr(const CordRep* r);
+  static absl::string_view EdgeData(const CordRep* r);
+
+  // Returns true if the provided rep is a FLAT, EXTERNAL or a SUBSTRING node
+  // holding a FLAT or EXTERNAL child rep.
+  static bool IsDataEdge(const CordRep* rep);
+
+  // Diagnostics: returns true if `tree` is valid and internally consistent.
+  // If `shallow` is false, then the provided top level node and all child nodes
+  // below it are recursively checked. If `shallow` is true, only the provided
+  // node in `tree` and the cumulative length, type and height of the direct
+  // child nodes of `tree` are checked. The value of `shallow` is ignored if the
+  // internal `cord_btree_exhaustive_validation` diagnostics variable is true,
+  // in which case the performed validations works as if `shallow` were false.
+  // This function is intended for debugging and testing purposes only.
+  static bool IsValid(const CordRepBtree* tree, bool shallow = false);
+
+  // Diagnostics: asserts that the provided tree is valid.
+  // `AssertValid()` performs a shallow validation by default. `shallow` can be
+  // set to false in which case an exhaustive validation is performed. This
+  // function is implemented in terms of calling `IsValid()` and asserting the
+  // return value to be true. See `IsValid()` for more information.
+  // This function is intended for debugging and testing purposes only.
+  static CordRepBtree* AssertValid(CordRepBtree* tree, bool shallow = true);
+  static const CordRepBtree* AssertValid(const CordRepBtree* tree,
+                                         bool shallow = true);
+
+  // Diagnostics: dump the contents of this tree to `stream`.
+  // This function is intended for debugging and testing purposes only.
+  static void Dump(const CordRep* rep, std::ostream& stream);
+  static void Dump(const CordRep* rep, absl::string_view label,
+                   std::ostream& stream);
+  static void Dump(const CordRep* rep, absl::string_view label,
+                   bool include_contents, std::ostream& stream);
+
+  // Adds the edge `edge` to this node if possible. `owned` indicates if the
+  // current node is potentially shared or not with other threads. Returns:
+  // - {kSelf, <this>}
+  //   The edge was directly added to this node.
+  // - {kCopied, <node>}
+  //   The edge was added to a copy of this node.
+  // - {kPopped, New(edge, height())}
+  //   A new leg with the edge was created as this node has no extra capacity.
+  template <EdgeType edge_type>
+  inline OpResult AddEdge(bool owned, CordRep* edge, size_t delta);
+
+  // Replaces the front or back edge with the provided new edge. Returns:
+  // - {kSelf, <this>}
+  //   The edge was directly set in this node. The old edge is unreffed.
+  // - {kCopied, <node>}
+  //   A copy of this node was created with the new edge value.
+  // In both cases, the function adopts a reference on `edge`.
+  template <EdgeType edge_type>
+  OpResult SetEdge(bool owned, CordRep* edge, size_t delta);
+
+  // Creates a new empty node at the specified height.
+  static CordRepBtree* New(int height = 0);
+
+  // Creates a new node containing `rep`, with the height being computed
+  // automatically based on the type of `rep`.
+  static CordRepBtree* New(CordRep* rep);
+
+  // Creates a new node containing both `front` and `back` at height
+  // `front.height() + 1`. Requires `back.height() == front.height()`.
+  static CordRepBtree* New(CordRepBtree* front, CordRepBtree* back);
+
+ private:
+  CordRepBtree() = default;
+  ~CordRepBtree() = default;
+
+  // Initializes the main properties `tag`, `begin`, `end`, `height`.
+  inline void InitInstance(int height, size_t begin = 0, size_t end = 0);
+
+  // Direct property access begin / end
+  void set_begin(size_t begin) { storage[1] = static_cast<uint8_t>(begin); }
+  void set_end(size_t end) { storage[2] = static_cast<uint8_t>(end); }
+
+  // Decreases the value of `begin` by `n`, and returns the new value. Notice
+  // how this returns the new value unlike atomic::fetch_add which returns the
+  // old value. This is because this is used to prepend edges at 'begin - 1'.
+  size_t sub_fetch_begin(size_t n) {
+    storage[1] -= static_cast<uint8_t>(n);
+    return storage[1];
+  }
+
+  // Increases the value of `end` by `n`, and returns the previous value. This
+  // function is typically used to append edges at 'end'.
+  size_t fetch_add_end(size_t n) {
+    const uint8_t current = storage[2];
+    storage[2] = static_cast<uint8_t>(current + n);
+    return current;
+  }
+
+  // Returns the index of the last edge starting on, or before `offset`, with
+  // `n` containing the relative offset of `offset` inside that edge.
+  // Requires `offset` < length.
+  Position IndexOf(size_t offset) const;
+
+  // Returns the index of the last edge starting before `offset`, with `n`
+  // containing the relative offset of `offset` inside that edge.
+  // This function is useful to find the edges for some span of bytes ending at
+  // `offset` (i.e., `n` bytes). For example:
+  //
+  //   Position pos = IndexBefore(n)
+  //   edges = Edges(begin(), pos.index)     // All full edges (may be empty)
+  //   last = Sub(Edge(pos.index), 0, pos.n) // Last partial edge (may be empty)
+  //
+  // Requires 0 < `offset` <= length.
+  Position IndexBefore(size_t offset) const;
+
+  // Identical to the above function except starting from the position `front`.
+  // This function is equivalent to `IndexBefore(front.n + offset)`, with
+  // the difference that this function is optimized to start at `front.index`.
+  Position IndexBefore(Position front, size_t offset) const;
+
+  // Returns the index of the edge directly beyond the edge containing offset
+  // `offset`, with `n` containing the distance of that edge from `offset`.
+  // This function is useful for iteratively finding suffix nodes and remaining
+  // partial bytes in left-most suffix nodes as for example in CopySuffix.
+  // Requires `offset` < length.
+  Position IndexBeyond(size_t offset) const;
+
+  // Destruction
+  static void DestroyLeaf(CordRepBtree* tree, size_t begin, size_t end);
+  static void DestroyNonLeaf(CordRepBtree* tree, size_t begin, size_t end);
+  static void DestroyTree(CordRepBtree* tree, size_t begin, size_t end);
+  static void Delete(CordRepBtree* tree) { delete tree; }
+
+  // Creates a new leaf node containing as much data as possible from `data`.
+  // The data is added either forwards or reversed depending on `edge_type`.
+  // Callers must check the length of the returned node to determine if all data
+  // was copied or not.
+  // See the `Append/Prepend` function for the meaning and purpose of `extra`.
+  template <EdgeType edge_type>
+  static CordRepBtree* NewLeaf(absl::string_view data, size_t extra);
+
+  // Creates a raw copy of this Btree node, copying all properties, but
+  // without adding any references to existing edges.
+  CordRepBtree* CopyRaw() const;
+
+  // Creates a full copy of this Btree node, adding a reference on all edges.
+  CordRepBtree* Copy() const;
+
+  // Creates a partial copy of this Btree node, copying all edges up to `end`,
+  // adding a reference on each copied edge, and sets the length of the newly
+  // created copy to `new_length`.
+  CordRepBtree* CopyBeginTo(size_t end, size_t new_length) const;
+
+  // Creates a partial copy of this Btree node, copying all edges starting at
+  // `begin`, adding a reference on each copied edge, and sets the length of
+  // the newly created copy to `new_length`.
+  CordRepBtree* CopyToEndFrom(size_t begin, size_t new_length) const;
+
+  // Returns a tree containing the result of appending `right` to `left`.
+  static CordRepBtree* MergeTrees(CordRepBtree* left, CordRepBtree* right);
+
+  // Fallback functions for `Create()`, `Append()` and `Prepend()` which
+  // deal with legacy / non conforming input, i.e.: CONCAT trees.
+  static CordRepBtree* CreateSlow(CordRep* rep);
+  static CordRepBtree* AppendSlow(CordRepBtree*, CordRep* rep);
+  static CordRepBtree* PrependSlow(CordRepBtree*, CordRep* rep);
+
+  // Aligns existing edges to start at index 0, to allow for a new edge to be
+  // added to the back of the current edges.
+  inline void AlignBegin();
+
+  // Aligns existing edges to end at `capacity`, to allow for a new edge to be
+  // added in front of the current edges.
+  inline void AlignEnd();
+
+  // Adds the provided edge to this node.
+  // Requires this node to have capacity for the edge. Realigns / moves
+  // existing edges as needed to prepend or append the new edge.
+  template <EdgeType edge_type>
+  inline void Add(CordRep* rep);
+
+  // Adds the provided edges to this node.
+  // Requires this node to have capacity for the edges. Realigns / moves
+  // existing edges as needed to prepend or append the new edges.
+  template <EdgeType edge_type>
+  inline void Add(absl::Span<CordRep* const>);
+
+  // Adds data from `data` to this node until either all data has been consumed,
+  // or there is no more capacity for additional flat nodes inside this node.
+  // Requires the current node to be a leaf node, data to be non empty, and the
+  // current node to have capacity for at least one more data edge.
+  // Returns any remaining data from `data` that was not added, which is
+  // depending on the edge type (front / back) either the remaining prefix of
+  // suffix of the input.
+  // See the `Append/Prepend` function for the meaning and purpose of `extra`.
+  template <EdgeType edge_type>
+  absl::string_view AddData(absl::string_view data, size_t extra);
+
+  // Replace the front or back edge with the provided value.
+  // Adopts a reference on `edge` and unrefs the old edge.
+  template <EdgeType edge_type>
+  inline void SetEdge(CordRep* edge);
+
+  // Returns a partial copy of the current tree containing the first `n` bytes
+  // of data. `CopyResult` contains both the resulting edge and its height. The
+  // resulting tree may be less high than the current tree, or even be a single
+  // matching data edge. For example, if `n == 1`, then the result will be the
+  // single data edge, and height will be set to -1 (one below the owning leaf
+  // node). If n == 0, this function returns null.
+  // Requires `n <= length`
+  CopyResult CopyPrefix(size_t n);
+
+  // Returns a partial copy of the current tree containing all data starting
+  // after `offset`. `CopyResult` contains both the resulting edge and its
+  // height. The resulting tree may be less high than the current tree, or even
+  // be a single matching data edge. For example, if `n == length - 1`, then the
+  // result will be a single data edge, and height will be set to -1 (one below
+  // the owning leaf node).
+  // Requires `offset < length`
+  CopyResult CopySuffix(size_t offset);
+
+  // Returns a OpResult value of {this, kSelf} or {Copy(), kCopied}
+  // depending on the value of `owned`.
+  inline OpResult ToOpResult(bool owned);
+
+  // Adds `rep` to the specified tree, returning the modified tree.
+  template <EdgeType edge_type>
+  static CordRepBtree* AddCordRep(CordRepBtree* tree, CordRep* rep);
+
+  // Adds `data` to the specified tree, returning the modified tree.
+  // See the `Append/Prepend` function for the meaning and purpose of `extra`.
+  template <EdgeType edge_type>
+  static CordRepBtree* AddData(CordRepBtree* tree, absl::string_view data,
+                               size_t extra = 0);
+
+  // Merges `src` into `dst` with `src` being added either before (kFront) or
+  // after (kBack) `dst`. Requires the height of `dst` to be greater than or
+  // equal to the height of `src`.
+  template <EdgeType edge_type>
+  static CordRepBtree* Merge(CordRepBtree* dst, CordRepBtree* src);
+
+  // Fallback version of GetAppendBuffer for large trees: GetAppendBuffer()
+  // implements an inlined version for trees of limited height (3 levels),
+  // GetAppendBufferSlow implements the logic for large trees.
+  Span<char> GetAppendBufferSlow(size_t size);
+
+  // `edges_` contains all edges starting from this instance.
+  // These are explicitly `child` edges only, a cord btree (or any cord tree in
+  // that respect) does not store `parent` pointers anywhere: multiple trees /
+  // parents can reference the same shared child edge. The type of these edges
+  // depends on the height of the node. `Leaf nodes` (height == 0) contain `data
+  // edges` (external or flat nodes, or sub-strings thereof). All other nodes
+  // (height > 0) contain pointers to BTREE nodes with a height of `height - 1`.
+  CordRep* edges_[kMaxCapacity];
+
+  friend class CordRepBtreeTestPeer;
+  friend class CordRepBtreeNavigator;
+};
+
+inline CordRepBtree* CordRep::btree() {
+  assert(IsBtree());
+  return static_cast<CordRepBtree*>(this);
+}
+
+inline const CordRepBtree* CordRep::btree() const {
+  assert(IsBtree());
+  return static_cast<const CordRepBtree*>(this);
+}
+
+inline void CordRepBtree::InitInstance(int height, size_t begin, size_t end) {
+  tag = BTREE;
+  storage[0] = static_cast<uint8_t>(height);
+  storage[1] = static_cast<uint8_t>(begin);
+  storage[2] = static_cast<uint8_t>(end);
+}
+
+inline CordRep* CordRepBtree::Edge(size_t index) const {
+  assert(index >= begin());
+  assert(index < end());
+  return edges_[index];
+}
+
+inline CordRep* CordRepBtree::Edge(EdgeType edge_type) const {
+  return edges_[edge_type == kFront ? begin() : back()];
+}
+
+inline absl::Span<CordRep* const> CordRepBtree::Edges() const {
+  return {edges_ + begin(), size()};
+}
+
+inline absl::Span<CordRep* const> CordRepBtree::Edges(size_t begin,
+                                                      size_t end) const {
+  assert(begin <= end);
+  assert(begin >= this->begin());
+  assert(end <= this->end());
+  return {edges_ + begin, static_cast<size_t>(end - begin)};
+}
+
+inline const char* CordRepBtree::EdgeDataPtr(const CordRep* r) {
+  assert(IsDataEdge(r));
+  size_t offset = 0;
+  if (r->tag == SUBSTRING) {
+    offset = r->substring()->start;
+    r = r->substring()->child;
+  }
+  return (r->tag >= FLAT ? r->flat()->Data() : r->external()->base) + offset;
+}
+
+inline absl::string_view CordRepBtree::EdgeData(const CordRep* r) {
+  return absl::string_view(EdgeDataPtr(r), r->length);
+}
+
+inline absl::string_view CordRepBtree::Data(size_t index) const {
+  assert(height() == 0);
+  return EdgeData(Edge(index));
+}
+
+inline bool CordRepBtree::IsDataEdge(const CordRep* rep) {
+  // The fast path is that `rep` is an EXTERNAL or FLAT node, making the below
+  // if a single, well predicted branch. We then repeat the FLAT or EXTERNAL
+  // check in the slow path the SUBSTRING check to optimize for the hot path.
+  if (rep->tag == EXTERNAL || rep->tag >= FLAT) return true;
+  if (rep->tag == SUBSTRING) rep = rep->substring()->child;
+  return rep->tag == EXTERNAL || rep->tag >= FLAT;
+}
+
+inline CordRepBtree* CordRepBtree::New(int height) {
+  CordRepBtree* tree = new CordRepBtree;
+  tree->length = 0;
+  tree->InitInstance(height);
+  return tree;
+}
+
+inline CordRepBtree* CordRepBtree::New(CordRep* rep) {
+  CordRepBtree* tree = new CordRepBtree;
+  int height = rep->IsBtree() ? rep->btree()->height() + 1 : 0;
+  tree->length = rep->length;
+  tree->InitInstance(height, /*begin=*/0, /*end=*/1);
+  tree->edges_[0] = rep;
+  return tree;
+}
+
+inline CordRepBtree* CordRepBtree::New(CordRepBtree* front,
+                                       CordRepBtree* back) {
+  assert(front->height() == back->height());
+  CordRepBtree* tree = new CordRepBtree;
+  tree->length = front->length + back->length;
+  tree->InitInstance(front->height() + 1, /*begin=*/0, /*end=*/2);
+  tree->edges_[0] = front;
+  tree->edges_[1] = back;
+  return tree;
+}
+
+inline void CordRepBtree::DestroyTree(CordRepBtree* tree, size_t begin,
+                                      size_t end) {
+  if (tree->height() == 0) {
+    DestroyLeaf(tree, begin, end);
+  } else {
+    DestroyNonLeaf(tree, begin, end);
+  }
+}
+
+inline void CordRepBtree::Destroy(CordRepBtree* tree) {
+  DestroyTree(tree, tree->begin(), tree->end());
+}
+
+inline CordRepBtree* CordRepBtree::CopyRaw() const {
+  auto* tree = static_cast<CordRepBtree*>(::operator new(sizeof(CordRepBtree)));
+  memcpy(static_cast<void*>(tree), this, sizeof(CordRepBtree));
+  new (&tree->refcount) Refcount;
+  return tree;
+}
+
+inline CordRepBtree* CordRepBtree::Copy() const {
+  CordRepBtree* tree = CopyRaw();
+  for (CordRep* rep : Edges()) CordRep::Ref(rep);
+  return tree;
+}
+
+inline CordRepBtree* CordRepBtree::CopyToEndFrom(size_t begin,
+                                                 size_t new_length) const {
+  assert(begin >= this->begin());
+  assert(begin <= this->end());
+  CordRepBtree* tree = CopyRaw();
+  tree->length = new_length;
+  tree->set_begin(begin);
+  for (CordRep* edge : tree->Edges()) CordRep::Ref(edge);
+  return tree;
+}
+
+inline CordRepBtree* CordRepBtree::CopyBeginTo(size_t end,
+                                               size_t new_length) const {
+  assert(end <= capacity());
+  assert(end >= this->begin());
+  CordRepBtree* tree = CopyRaw();
+  tree->length = new_length;
+  tree->set_end(end);
+  for (CordRep* edge : tree->Edges()) CordRep::Ref(edge);
+  return tree;
+}
+
+inline void CordRepBtree::AlignBegin() {
+  // The below code itself does not need to be fast as typically we have
+  // mono-directional append/prepend calls, and `begin` / `end` are typically
+  // adjusted no more than once. But we want to avoid potential register clobber
+  // effects, making the compiler emit register save/store/spills, and minimize
+  // the size of code.
+  const size_t delta = begin();
+  if (ABSL_PREDICT_FALSE(delta != 0)) {
+    const size_t new_end = end() - delta;
+    set_begin(0);
+    set_end(new_end);
+    // TODO(mvels): we can write this using 2 loads / 2 stores depending on
+    // total size for the kMaxCapacity = 6 case. I.e., we can branch (switch) on
+    // size, and then do overlapping load/store of up to 4 pointers (inlined as
+    // XMM, YMM or ZMM load/store) and up to 2 pointers (XMM / YMM), which is a)
+    // compact and b) not clobbering any registers.
+    ABSL_INTERNAL_ASSUME(new_end <= kMaxCapacity);
+#ifdef __clang__
+#pragma unroll 1
+#endif
+    for (size_t i = 0; i < new_end; ++i) {
+      edges_[i] = edges_[i + delta];
+    }
+  }
+}
+
+inline void CordRepBtree::AlignEnd() {
+  // See comments in `AlignBegin` for motivation on the hand-rolled for loops.
+  const size_t delta = capacity() - end();
+  if (delta != 0) {
+    const size_t new_begin = begin() + delta;
+    const size_t new_end = end() + delta;
+    set_begin(new_begin);
+    set_end(new_end);
+    ABSL_INTERNAL_ASSUME(new_end <= kMaxCapacity);
+#ifdef __clang__
+#pragma unroll 1
+#endif
+    for (size_t i = new_end - 1; i >= new_begin; --i) {
+      edges_[i] = edges_[i - delta];
+    }
+  }
+}
+
+template <>
+inline void CordRepBtree::Add<CordRepBtree::kBack>(CordRep* rep) {
+  AlignBegin();
+  edges_[fetch_add_end(1)] = rep;
+}
+
+template <>
+inline void CordRepBtree::Add<CordRepBtree::kBack>(
+    absl::Span<CordRep* const> edges) {
+  AlignBegin();
+  size_t new_end = end();
+  for (CordRep* edge : edges) edges_[new_end++] = edge;
+  set_end(new_end);
+}
+
+template <>
+inline void CordRepBtree::Add<CordRepBtree::kFront>(CordRep* rep) {
+  AlignEnd();
+  edges_[sub_fetch_begin(1)] = rep;
+}
+
+template <>
+inline void CordRepBtree::Add<CordRepBtree::kFront>(
+    absl::Span<CordRep* const> edges) {
+  AlignEnd();
+  size_t new_begin = begin() - edges.size();
+  set_begin(new_begin);
+  for (CordRep* edge : edges) edges_[new_begin++] = edge;
+}
+
+template <CordRepBtree::EdgeType edge_type>
+inline void CordRepBtree::SetEdge(CordRep* edge) {
+  const int idx = edge_type == kFront ? begin() : back();
+  CordRep::Unref(edges_[idx]);
+  edges_[idx] = edge;
+}
+
+inline CordRepBtree::OpResult CordRepBtree::ToOpResult(bool owned) {
+  return owned ? OpResult{this, kSelf} : OpResult{Copy(), kCopied};
+}
+
+inline CordRepBtree::Position CordRepBtree::IndexOf(size_t offset) const {
+  assert(offset < length);
+  size_t index = begin();
+  while (offset >= edges_[index]->length) offset -= edges_[index++]->length;
+  return {index, offset};
+}
+
+inline CordRepBtree::Position CordRepBtree::IndexBefore(size_t offset) const {
+  assert(offset > 0);
+  assert(offset <= length);
+  size_t index = begin();
+  while (offset > edges_[index]->length) offset -= edges_[index++]->length;
+  return {index, offset};
+}
+
+inline CordRepBtree::Position CordRepBtree::IndexBefore(Position front,
+                                                        size_t offset) const {
+  size_t index = front.index;
+  offset = offset + front.n;
+  while (offset > edges_[index]->length) offset -= edges_[index++]->length;
+  return {index, offset};
+}
+
+inline CordRepBtree::Position CordRepBtree::IndexBeyond(
+    const size_t offset) const {
+  // We need to find the edge which `starting offset` is beyond (>=)`offset`.
+  // For this we can't use the `offset -= length` logic of IndexOf. Instead, we
+  // track the offset of the `current edge` in `off`, which we increase as we
+  // iterate over the edges until we find the matching edge.
+  size_t off = 0;
+  size_t index = begin();
+  while (offset > off) off += edges_[index++]->length;
+  return {index, off - offset};
+}
+
+inline CordRepBtree* CordRepBtree::Create(CordRep* rep) {
+  if (IsDataEdge(rep)) return New(rep);
+  return CreateSlow(rep);
+}
+
+inline Span<char> CordRepBtree::GetAppendBuffer(size_t size) {
+  assert(refcount.IsOne());
+  CordRepBtree* tree = this;
+  const int height = this->height();
+  CordRepBtree* n1 = tree;
+  CordRepBtree* n2 = tree;
+  CordRepBtree* n3 = tree;
+  switch (height) {
+    case 3:
+      tree = tree->Edge(kBack)->btree();
+      if (!tree->refcount.IsOne()) return {};
+      n2 = tree;
+      ABSL_FALLTHROUGH_INTENDED;
+    case 2:
+      tree = tree->Edge(kBack)->btree();
+      if (!tree->refcount.IsOne()) return {};
+      n1 = tree;
+      ABSL_FALLTHROUGH_INTENDED;
+    case 1:
+      tree = tree->Edge(kBack)->btree();
+      if (!tree->refcount.IsOne()) return {};
+      ABSL_FALLTHROUGH_INTENDED;
+    case 0:
+      CordRep* edge = tree->Edge(kBack);
+      if (!edge->refcount.IsOne()) return {};
+      if (edge->tag < FLAT) return {};
+      size_t avail = edge->flat()->Capacity() - edge->length;
+      if (avail == 0) return {};
+      size_t delta = (std::min)(size, avail);
+      Span<char> span = {edge->flat()->Data() + edge->length, delta};
+      edge->length += delta;
+      switch (height) {
+        case 3:
+          n3->length += delta;
+          ABSL_FALLTHROUGH_INTENDED;
+        case 2:
+          n2->length += delta;
+          ABSL_FALLTHROUGH_INTENDED;
+        case 1:
+          n1->length += delta;
+          ABSL_FALLTHROUGH_INTENDED;
+        case 0:
+          tree->length += delta;
+          return span;
+      }
+      break;
+  }
+  return GetAppendBufferSlow(size);
+}
+
+extern template CordRepBtree* CordRepBtree::AddCordRep<CordRepBtree::kBack>(
+    CordRepBtree* tree, CordRep* rep);
+
+extern template CordRepBtree* CordRepBtree::AddCordRep<CordRepBtree::kFront>(
+    CordRepBtree* tree, CordRep* rep);
+
+inline CordRepBtree* CordRepBtree::Append(CordRepBtree* tree, CordRep* rep) {
+  if (ABSL_PREDICT_TRUE(IsDataEdge(rep))) {
+    return CordRepBtree::AddCordRep<kBack>(tree, rep);
+  }
+  return AppendSlow(tree, rep);
+}
+
+inline CordRepBtree* CordRepBtree::Prepend(CordRepBtree* tree, CordRep* rep) {
+  if (ABSL_PREDICT_TRUE(IsDataEdge(rep))) {
+    return CordRepBtree::AddCordRep<kFront>(tree, rep);
+  }
+  return PrependSlow(tree, rep);
+}
+
+#ifdef NDEBUG
+
+inline CordRepBtree* CordRepBtree::AssertValid(CordRepBtree* tree,
+                                               bool /* shallow */) {
+  return tree;
+}
+
+inline const CordRepBtree* CordRepBtree::AssertValid(const CordRepBtree* tree,
+                                                     bool /* shallow */) {
+  return tree;
+}
+
+#endif
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_H_
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.cc
new file mode 100644
index 00000000000..d1f9995d00e
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.cc
@@ -0,0 +1,185 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree_navigator.h"
+
+#include <cassert>
+
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+using ReadResult = CordRepBtreeNavigator::ReadResult;
+
+namespace {
+
+// Returns a `CordRepSubstring` from `rep` starting at `offset` of size `n`.
+// If `rep` is already a `CordRepSubstring` instance, an adjusted instance is
+// created based on the old offset and new offset.
+// Adopts a reference on `rep`. Rep must be a valid data edge. Returns
+// nullptr if `n == 0`, `rep` if `n == rep->length`.
+// Requires `offset < rep->length` and `offset + n <= rep->length`.
+// TODO(192061034): move to utility library in internal and optimize for small
+// substrings of larger reps.
+inline CordRep* Substring(CordRep* rep, size_t offset, size_t n) {
+  assert(n <= rep->length);
+  assert(offset < rep->length);
+  assert(offset <= rep->length - n);
+  assert(CordRepBtree::IsDataEdge(rep));
+
+  if (n == 0) return nullptr;
+  if (n == rep->length) return CordRep::Ref(rep);
+
+  if (rep->tag == SUBSTRING) {
+    offset += rep->substring()->start;
+    rep = rep->substring()->child;
+  }
+
+  CordRepSubstring* substring = new CordRepSubstring();
+  substring->length = n;
+  substring->tag = SUBSTRING;
+  substring->start = offset;
+  substring->child = CordRep::Ref(rep);
+  return substring;
+}
+
+inline CordRep* Substring(CordRep* rep, size_t offset) {
+  return Substring(rep, offset, rep->length - offset);
+}
+
+}  // namespace
+
+CordRepBtreeNavigator::Position CordRepBtreeNavigator::Skip(size_t n) {
+  int height = 0;
+  size_t index = index_[0];
+  CordRepBtree* node = node_[0];
+  CordRep* edge = node->Edge(index);
+
+  // Overall logic: Find an edge of at least the length we need to skip.
+  // We consume all edges which are smaller (i.e., must be 100% skipped).
+  // If we exhausted all edges on the current level, we move one level
+  // up the tree, and repeat until we either find the edge, or until we hit
+  // the top of the tree meaning the skip exceeds tree->length.
+  while (n >= edge->length) {
+    n -= edge->length;
+    while (++index == node->end()) {
+      if (++height > height_) return {nullptr, n};
+      node = node_[height];
+      index = index_[height];
+    }
+    edge = node->Edge(index);
+  }
+
+  // If we moved up the tree, descend down to the leaf level, consuming all
+  // edges that must be skipped.
+  while (height > 0) {
+    node = edge->btree();
+    index_[height] = index;
+    node_[--height] = node;
+    index = node->begin();
+    edge = node->Edge(index);
+    while (n >= edge->length) {
+      n -= edge->length;
+      ++index;
+      assert(index != node->end());
+      edge = node->Edge(index);
+    }
+  }
+  index_[0] = index;
+  return {edge, n};
+}
+
+ReadResult CordRepBtreeNavigator::Read(size_t edge_offset, size_t n) {
+  int height = 0;
+  size_t length = edge_offset + n;
+  size_t index = index_[0];
+  CordRepBtree* node = node_[0];
+  CordRep* edge = node->Edge(index);
+  assert(edge_offset < edge->length);
+
+  if (length < edge->length) {
+    return {Substring(edge, edge_offset, n), length};
+  }
+
+  // Similar to 'Skip', we consume all edges that are inside the 'length' of
+  // data that needs to be read. If we exhaust the current level, we move one
+  // level up the tree and repeat until we hit the final edge that must be
+  // (partially) read. We consume all edges into `subtree`.
+  CordRepBtree* subtree = CordRepBtree::New(Substring(edge, edge_offset));
+  size_t subtree_end = 1;
+  do {
+    length -= edge->length;
+    while (++index == node->end()) {
+      index_[height] = index;
+      if (++height > height_) {
+        subtree->set_end(subtree_end);
+        if (length == 0) return {subtree, 0};
+        CordRep::Unref(subtree);
+        return {nullptr, length};
+      }
+      if (length != 0) {
+        subtree->set_end(subtree_end);
+        subtree = CordRepBtree::New(subtree);
+        subtree_end = 1;
+      }
+      node = node_[height];
+      index = index_[height];
+    }
+    edge = node->Edge(index);
+    if (length >= edge->length) {
+      subtree->length += edge->length;
+      subtree->edges_[subtree_end++] = CordRep::Ref(edge);
+    }
+  } while (length >= edge->length);
+  CordRepBtree* tree = subtree;
+  subtree->length += length;
+
+  // If we moved up the tree, descend down to the leaf level, consuming all
+  // edges that must be read, adding 'down' nodes to `subtree`.
+  while (height > 0) {
+    node = edge->btree();
+    index_[height] = index;
+    node_[--height] = node;
+    index = node->begin();
+    edge = node->Edge(index);
+
+    if (length != 0) {
+      CordRepBtree* right = CordRepBtree::New(height);
+      right->length = length;
+      subtree->edges_[subtree_end++] = right;
+      subtree->set_end(subtree_end);
+      subtree = right;
+      subtree_end = 0;
+      while (length >= edge->length) {
+        subtree->edges_[subtree_end++] = CordRep::Ref(edge);
+        length -= edge->length;
+        edge = node->Edge(++index);
+      }
+    }
+  }
+  // Add any (partial) edge still remaining at the leaf level.
+  if (length != 0) {
+    subtree->edges_[subtree_end++] = Substring(edge, 0, length);
+  }
+  subtree->set_end(subtree_end);
+  index_[0] = index;
+  return {tree, length};
+}
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.h
new file mode 100644
index 00000000000..971b92eda6d
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.h
@@ -0,0 +1,265 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_
+#define ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_
+
+#include <cassert>
+#include <iostream>
+
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+// CordRepBtreeNavigator is a bi-directional navigator allowing callers to
+// navigate all the (leaf) data edges in a CordRepBtree instance.
+//
+// A CordRepBtreeNavigator instance is by default empty. Callers initialize a
+// navigator instance by calling one of `InitFirst()`, `InitLast()` or
+// `InitOffset()`, which establishes a current position. Callers can then
+// navigate using the `Next`, `Previous`, `Skip` and `Seek` methods.
+//
+// The navigator instance does not take or adopt a reference on the provided
+// `tree` on any of the initialization calls. Callers are responsible for
+// guaranteeing the lifecycle of the provided tree. A navigator instance can
+// be reset to the empty state by calling `Reset`.
+//
+// A navigator only keeps positional state on the 'current data edge', it does
+// explicitly not keep any 'offset' state. The class does accept and return
+// offsets in the `Read()`, `Skip()` and 'Seek()` methods as these would
+// otherwise put a big burden on callers. Callers are expected to maintain
+// (returned) offset info if they require such granular state.
+class CordRepBtreeNavigator {
+ public:
+  // The logical position as returned by the Seek() and Skip() functions.
+  // Returns the current leaf edge for the desired seek or skip position and
+  // the offset of that position inside that edge.
+  struct Position {
+    CordRep* edge;
+    size_t offset;
+  };
+
+  // The read result as returned by the Read() function.
+  // `tree` contains the resulting tree which is identical to the result
+  // of calling CordRepBtree::SubTree(...) on the tree being navigated.
+  // `n` contains the number of bytes used from the last navigated to
+  // edge of the tree.
+  struct ReadResult {
+    CordRep* tree;
+    size_t n;
+  };
+
+  // Returns true if this instance is not empty.
+  explicit operator bool() const;
+
+  // Returns the tree for this instance or nullptr if empty.
+  CordRepBtree* btree() const;
+
+  // Returns the data edge of the current position.
+  // Requires this instance to not be empty.
+  CordRep* Current() const;
+
+  // Resets this navigator to `tree`, returning the first data edge in the tree.
+  CordRep* InitFirst(CordRepBtree* tree);
+
+  // Resets this navigator to `tree`, returning the last data edge in the tree.
+  CordRep* InitLast(CordRepBtree* tree);
+
+  // Resets this navigator to `tree` returning the data edge at position
+  // `offset` and the relative offset of `offset` into that data edge.
+  // Returns `Position.edge = nullptr` if the provided offset is greater
+  // than or equal to the length of the tree, in which case the state of
+  // the navigator instance remains unchanged.
+  Position InitOffset(CordRepBtree* tree, size_t offset);
+
+  // Navigates to the next data edge.
+  // Returns the next data edge or nullptr if there is no next data edge, in
+  // which case the current position remains unchanged.
+  CordRep* Next();
+
+  // Navigates to the previous data edge.
+  // Returns the previous data edge or nullptr if there is no previous data
+  // edge, in which case the current position remains unchanged.
+  CordRep* Previous();
+
+  // Navigates to the data edge at position `offset`. Returns the navigated to
+  // data edge in `Position.edge` and the relative offset of `offset` into that
+  // data edge in `Position.offset`. Returns `Position.edge = nullptr` if the
+  // provide offset is greater than or equal to the tree's length.
+  Position Seek(size_t offset);
+
+  // Reads `n` bytes of data starting at offset `edge_offset` of the current
+  // data edge, and returns the result in `ReadResult.tree`. `ReadResult.n`
+  // contains the 'bytes used` from the last / current data edge in the tree.
+  // This allows users that mix regular navigation (using string views) and
+  // 'read into cord' navigation to keep track of the current state, and which
+  // bytes have been consumed from a navigator.
+  // This function returns `ReadResult.tree = nullptr` if the requested length
+  // exceeds the length of the tree starting at the current data edge.
+  ReadResult Read(size_t edge_offset, size_t n);
+
+  // Skips `n` bytes forward from the current data edge, returning the navigated
+  // to data edge in `Position.edge` and `Position.offset` containing the offset
+  // inside that data edge. Note that the state of the navigator is left
+  // unchanged if `n` is smaller than the length of the current data edge.
+  Position Skip(size_t n);
+
+  // Resets this instance to the default / empty state.
+  void Reset();
+
+ private:
+  // Slow path for Next() if Next() reached the end of a leaf node. Backtracks
+  // up the stack until it finds a node that has a 'next' position available,
+  // and then does a 'front dive' towards the next leaf node.
+  CordRep* NextUp();
+
+  // Slow path for Previous() if Previous() reached the beginning of a leaf
+  // node. Backtracks up the stack until it finds a node that has a 'previous'
+  // position available, and then does a 'back dive' towards the previous leaf
+  // node.
+  CordRep* PreviousUp();
+
+  // Generic implementation of InitFirst() and InitLast().
+  template <CordRepBtree::EdgeType edge_type>
+  CordRep* Init(CordRepBtree* tree);
+
+  // `height_` contains the height of the current tree, or -1 if empty.
+  int height_ = -1;
+
+  // `index_` and `node_` contain the navigation state as the 'path' to the
+  // current data edge which is at `node_[0]->Edge(index_[0])`. The contents
+  // of these are undefined until the instance is initialized (`height_ >= 0`).
+  uint8_t index_[CordRepBtree::kMaxHeight];
+  CordRepBtree* node_[CordRepBtree::kMaxHeight];
+};
+
+// Returns true if this instance is not empty.
+inline CordRepBtreeNavigator::operator bool() const { return height_ >= 0; }
+
+inline CordRepBtree* CordRepBtreeNavigator::btree() const {
+  return height_ >= 0 ? node_[height_] : nullptr;
+}
+
+inline CordRep* CordRepBtreeNavigator::Current() const {
+  assert(height_ >= 0);
+  return node_[0]->Edge(index_[0]);
+}
+
+inline void CordRepBtreeNavigator::Reset() { height_ = -1; }
+
+inline CordRep* CordRepBtreeNavigator::InitFirst(CordRepBtree* tree) {
+  return Init<CordRepBtree::kFront>(tree);
+}
+
+inline CordRep* CordRepBtreeNavigator::InitLast(CordRepBtree* tree) {
+  return Init<CordRepBtree::kBack>(tree);
+}
+
+template <CordRepBtree::EdgeType edge_type>
+inline CordRep* CordRepBtreeNavigator::Init(CordRepBtree* tree) {
+  assert(tree != nullptr);
+  assert(tree->size() > 0);
+  int height = height_ = tree->height();
+  size_t index = tree->index(edge_type);
+  node_[height] = tree;
+  index_[height] = static_cast<uint8_t>(index);
+  while (--height >= 0) {
+    tree = tree->Edge(index)->btree();
+    node_[height] = tree;
+    index = tree->index(edge_type);
+    index_[height] = static_cast<uint8_t>(index);
+  }
+  return node_[0]->Edge(index);
+}
+
+inline CordRepBtreeNavigator::Position CordRepBtreeNavigator::Seek(
+    size_t offset) {
+  assert(btree() != nullptr);
+  int height = height_;
+  CordRepBtree* edge = node_[height];
+  if (ABSL_PREDICT_FALSE(offset >= edge->length)) return {nullptr, 0};
+  CordRepBtree::Position index = edge->IndexOf(offset);
+  index_[height] = static_cast<uint8_t>(index.index);
+  while (--height >= 0) {
+    edge = edge->Edge(index.index)->btree();
+    node_[height] = edge;
+    index = edge->IndexOf(index.n);
+    index_[height] = static_cast<uint8_t>(index.index);
+  }
+  return {edge->Edge(index.index), index.n};
+}
+
+inline CordRepBtreeNavigator::Position CordRepBtreeNavigator::InitOffset(
+    CordRepBtree* tree, size_t offset) {
+  assert(tree != nullptr);
+  if (ABSL_PREDICT_FALSE(offset >= tree->length)) return {nullptr, 0};
+  height_ = tree->height();
+  node_[height_] = tree;
+  return Seek(offset);
+}
+
+inline CordRep* CordRepBtreeNavigator::Next() {
+  CordRepBtree* edge = node_[0];
+  return index_[0] == edge->back() ? NextUp() : edge->Edge(++index_[0]);
+}
+
+inline CordRep* CordRepBtreeNavigator::Previous() {
+  CordRepBtree* edge = node_[0];
+  return index_[0] == edge->begin() ? PreviousUp() : edge->Edge(--index_[0]);
+}
+
+inline CordRep* CordRepBtreeNavigator::NextUp() {
+  assert(index_[0] == node_[0]->back());
+  CordRepBtree* edge;
+  size_t index;
+  int height = 0;
+  do {
+    if (++height > height_) return nullptr;
+    edge = node_[height];
+    index = index_[height] + 1;
+  } while (index == edge->end());
+  index_[height] = static_cast<uint8_t>(index);
+  do {
+    node_[--height] = edge = edge->Edge(index)->btree();
+    index_[height] = static_cast<uint8_t>(index = edge->begin());
+  } while (height > 0);
+  return edge->Edge(index);
+}
+
+inline CordRep* CordRepBtreeNavigator::PreviousUp() {
+  assert(index_[0] == node_[0]->begin());
+  CordRepBtree* edge;
+  size_t index;
+  int height = 0;
+  do {
+    if (++height > height_) return nullptr;
+    edge = node_[height];
+    index = index_[height];
+  } while (index == edge->begin());
+  index_[height] = static_cast<uint8_t>(--index);
+  do {
+    node_[--height] = edge = edge->Edge(index)->btree();
+    index_[height] = static_cast<uint8_t>(index = edge->back());
+  } while (height > 0);
+  return edge->Edge(index);
+}
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator_test.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator_test.cc
new file mode 100644
index 00000000000..ce09b1992a4
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator_test.cc
@@ -0,0 +1,325 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree_navigator.h"
+
+#include <string>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_test_util.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+namespace {
+
+using ::testing::Eq;
+using ::testing::Ne;
+
+using ::absl::cordrep_testing::CordRepBtreeFromFlats;
+using ::absl::cordrep_testing::CordToString;
+using ::absl::cordrep_testing::CreateFlatsFromString;
+using ::absl::cordrep_testing::CreateRandomString;
+using ::absl::cordrep_testing::MakeFlat;
+using ::absl::cordrep_testing::MakeSubstring;
+
+using ReadResult = CordRepBtreeNavigator::ReadResult;
+using Position = CordRepBtreeNavigator::Position;
+
+// CordRepBtreeNavigatorTest is a test fixture which automatically creates a
+// tree to test navigation logic on. The parameter `count' defines the number of
+// data edges in the test tree.
+class CordRepBtreeNavigatorTest : public testing::TestWithParam<int> {
+ public:
+  using Flats = std::vector<CordRep*>;
+  static constexpr size_t kCharsPerFlat = 3;
+
+  CordRepBtreeNavigatorTest() {
+    data_ = CreateRandomString(count() * kCharsPerFlat);
+    flats_ = CreateFlatsFromString(data_, kCharsPerFlat);
+
+    // Turn flat 0 or 1 into a substring to cover partial reads on substrings.
+    if (count() > 1) {
+      CordRep::Unref(flats_[1]);
+      flats_[1] = MakeSubstring(kCharsPerFlat, kCharsPerFlat, MakeFlat(data_));
+    } else {
+      CordRep::Unref(flats_[0]);
+      flats_[0] = MakeSubstring(0, kCharsPerFlat, MakeFlat(data_));
+    }
+
+    tree_ = CordRepBtreeFromFlats(flats_);
+  }
+
+  ~CordRepBtreeNavigatorTest() override { CordRep::Unref(tree_); }
+
+  int count() const { return GetParam(); }
+  CordRepBtree* tree() { return tree_; }
+  const std::string& data() const { return data_; }
+  const std::vector<CordRep*>& flats() const { return flats_; }
+
+  static std::string ToString(testing::TestParamInfo<int> param) {
+    return absl::StrCat(param.param, "_Flats");
+  }
+
+ private:
+  std::string data_;
+  Flats flats_;
+  CordRepBtree* tree_;
+};
+
+INSTANTIATE_TEST_SUITE_P(
+    WithParam, CordRepBtreeNavigatorTest,
+    testing::Values(1, CordRepBtree::kMaxCapacity - 1,
+                    CordRepBtree::kMaxCapacity,
+                    CordRepBtree::kMaxCapacity* CordRepBtree::kMaxCapacity - 1,
+                    CordRepBtree::kMaxCapacity* CordRepBtree::kMaxCapacity,
+                    CordRepBtree::kMaxCapacity* CordRepBtree::kMaxCapacity + 1,
+                    CordRepBtree::kMaxCapacity* CordRepBtree::kMaxCapacity * 2 +
+                        17),
+    CordRepBtreeNavigatorTest::ToString);
+
+TEST(CordRepBtreeNavigatorTest, Uninitialized) {
+  CordRepBtreeNavigator nav;
+  EXPECT_FALSE(nav);
+  EXPECT_THAT(nav.btree(), Eq(nullptr));
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+  EXPECT_DEATH(nav.Current(), ".*");
+#endif
+}
+
+TEST_P(CordRepBtreeNavigatorTest, InitFirst) {
+  CordRepBtreeNavigator nav;
+  CordRep* edge = nav.InitFirst(tree());
+  EXPECT_TRUE(nav);
+  EXPECT_THAT(nav.btree(), Eq(tree()));
+  EXPECT_THAT(nav.Current(), Eq(flats().front()));
+  EXPECT_THAT(edge, Eq(flats().front()));
+}
+
+TEST_P(CordRepBtreeNavigatorTest, InitLast) {
+  CordRepBtreeNavigator nav;
+  CordRep* edge = nav.InitLast(tree());
+  EXPECT_TRUE(nav);
+  EXPECT_THAT(nav.btree(), Eq(tree()));
+  EXPECT_THAT(nav.Current(), Eq(flats().back()));
+  EXPECT_THAT(edge, Eq(flats().back()));
+}
+
+TEST_P(CordRepBtreeNavigatorTest, NextPrev) {
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree());
+  const Flats& flats = this->flats();
+
+  EXPECT_THAT(nav.Previous(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.front()));
+  for (int i = 1; i < flats.size(); ++i) {
+    ASSERT_THAT(nav.Next(), Eq(flats[i]));
+    EXPECT_THAT(nav.Current(), Eq(flats[i]));
+  }
+  EXPECT_THAT(nav.Next(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.back()));
+  for (int i = static_cast<int>(flats.size()) - 2; i >= 0; --i) {
+    ASSERT_THAT(nav.Previous(), Eq(flats[i]));
+    EXPECT_THAT(nav.Current(), Eq(flats[i]));
+  }
+  EXPECT_THAT(nav.Previous(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.front()));
+}
+
+TEST_P(CordRepBtreeNavigatorTest, PrevNext) {
+  CordRepBtreeNavigator nav;
+  nav.InitLast(tree());
+  const Flats& flats = this->flats();
+
+  EXPECT_THAT(nav.Next(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.back()));
+  for (int i = static_cast<int>(flats.size()) - 2; i >= 0; --i) {
+    ASSERT_THAT(nav.Previous(), Eq(flats[i]));
+    EXPECT_THAT(nav.Current(), Eq(flats[i]));
+  }
+  EXPECT_THAT(nav.Previous(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.front()));
+  for (int i = 1; i < flats.size(); ++i) {
+    ASSERT_THAT(nav.Next(), Eq(flats[i]));
+    EXPECT_THAT(nav.Current(), Eq(flats[i]));
+  }
+  EXPECT_THAT(nav.Next(), Eq(nullptr));
+  EXPECT_THAT(nav.Current(), Eq(flats.back()));
+}
+
+TEST(CordRepBtreeNavigatorTest, Reset) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc"));
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree);
+  nav.Reset();
+  EXPECT_FALSE(nav);
+  EXPECT_THAT(nav.btree(), Eq(nullptr));
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+  EXPECT_DEATH(nav.Current(), ".*");
+#endif
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeNavigatorTest, Skip) {
+  int count = this->count();
+  const Flats& flats = this->flats();
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree());
+
+  for (int char_offset = 0; char_offset < kCharsPerFlat; ++char_offset) {
+    Position pos = nav.Skip(char_offset);
+    EXPECT_THAT(pos.edge, Eq(nav.Current()));
+    EXPECT_THAT(pos.edge, Eq(flats[0]));
+    EXPECT_THAT(pos.offset, Eq(char_offset));
+  }
+
+  for (int index1 = 0; index1 < count; ++index1) {
+    for (int index2 = index1; index2 < count; ++index2) {
+      for (int char_offset = 0; char_offset < kCharsPerFlat; ++char_offset) {
+        CordRepBtreeNavigator nav;
+        nav.InitFirst(tree());
+
+        size_t length1 = index1 * kCharsPerFlat;
+        Position pos1 = nav.Skip(length1 + char_offset);
+        ASSERT_THAT(pos1.edge, Eq(flats[index1]));
+        ASSERT_THAT(pos1.edge, Eq(nav.Current()));
+        ASSERT_THAT(pos1.offset, Eq(char_offset));
+
+        size_t length2 = index2 * kCharsPerFlat;
+        Position pos2 = nav.Skip(length2 - length1 + char_offset);
+        ASSERT_THAT(pos2.edge, Eq(flats[index2]));
+        ASSERT_THAT(pos2.edge, Eq(nav.Current()));
+        ASSERT_THAT(pos2.offset, Eq(char_offset));
+      }
+    }
+  }
+}
+
+TEST_P(CordRepBtreeNavigatorTest, Seek) {
+  int count = this->count();
+  const Flats& flats = this->flats();
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree());
+
+  for (int char_offset = 0; char_offset < kCharsPerFlat; ++char_offset) {
+    Position pos = nav.Seek(char_offset);
+    EXPECT_THAT(pos.edge, Eq(nav.Current()));
+    EXPECT_THAT(pos.edge, Eq(flats[0]));
+    EXPECT_THAT(pos.offset, Eq(char_offset));
+  }
+
+  for (int index = 0; index < count; ++index) {
+    for (int char_offset = 0; char_offset < kCharsPerFlat; ++char_offset) {
+      size_t offset = index * kCharsPerFlat + char_offset;
+      Position pos1 = nav.Seek(offset);
+      ASSERT_THAT(pos1.edge, Eq(flats[index]));
+      ASSERT_THAT(pos1.edge, Eq(nav.Current()));
+      ASSERT_THAT(pos1.offset, Eq(char_offset));
+    }
+  }
+}
+
+TEST(CordRepBtreeNavigatorTest, InitOffset) {
+  // Whitebox: InitOffset() is implemented in terms of Seek() which is
+  // exhaustively tested. Only test it initializes / forwards properly..
+  CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc"));
+  tree = CordRepBtree::Append(tree, MakeFlat("def"));
+  CordRepBtreeNavigator nav;
+  Position pos = nav.InitOffset(tree, 5);
+  EXPECT_TRUE(nav);
+  EXPECT_THAT(nav.btree(), Eq(tree));
+  EXPECT_THAT(pos.edge, Eq(tree->Edges()[1]));
+  EXPECT_THAT(pos.edge, Eq(nav.Current()));
+  EXPECT_THAT(pos.offset, Eq(2));
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeNavigatorTest, InitOffsetAndSeekBeyondLength) {
+  CordRepBtree* tree1 = CordRepBtree::Create(MakeFlat("abc"));
+  CordRepBtree* tree2 = CordRepBtree::Create(MakeFlat("def"));
+
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree1);
+  EXPECT_THAT(nav.Seek(3).edge, Eq(nullptr));
+  EXPECT_THAT(nav.Seek(100).edge, Eq(nullptr));
+  EXPECT_THAT(nav.btree(), Eq(tree1));
+  EXPECT_THAT(nav.Current(), Eq(tree1->Edges().front()));
+
+  EXPECT_THAT(nav.InitOffset(tree2, 3).edge, Eq(nullptr));
+  EXPECT_THAT(nav.InitOffset(tree2, 100).edge, Eq(nullptr));
+  EXPECT_THAT(nav.btree(), Eq(tree1));
+  EXPECT_THAT(nav.Current(), Eq(tree1->Edges().front()));
+
+  CordRep::Unref(tree1);
+  CordRep::Unref(tree2);
+}
+
+TEST_P(CordRepBtreeNavigatorTest, Read) {
+  const Flats& flats = this->flats();
+  const std::string& data = this->data();
+
+  for (size_t offset = 0; offset < data.size(); ++offset) {
+    for (size_t length = 1; length <= data.size() - offset; ++length) {
+      CordRepBtreeNavigator nav;
+      nav.InitFirst(tree());
+
+      // Skip towards edge holding offset
+      size_t edge_offset = nav.Skip(offset).offset;
+
+      // Read node
+      ReadResult result = nav.Read(edge_offset, length);
+      ASSERT_THAT(result.tree, Ne(nullptr));
+      EXPECT_THAT(result.tree->length, Eq(length));
+      if (result.tree->tag == BTREE) {
+        ASSERT_TRUE(CordRepBtree::IsValid(result.tree->btree()));
+      }
+
+      // Verify contents
+      std::string value = CordToString(result.tree);
+      EXPECT_THAT(value, Eq(data.substr(offset, length)));
+
+      // Verify 'partial last edge' reads.
+      size_t partial = (offset + length) % kCharsPerFlat;
+      ASSERT_THAT(result.n, Eq(partial));
+
+      // Verify ending position if not EOF
+      if (offset + length < data.size()) {
+        size_t index = (offset + length) / kCharsPerFlat;
+        EXPECT_THAT(nav.Current(), Eq(flats[index]));
+      }
+
+      CordRep::Unref(result.tree);
+    }
+  }
+}
+
+TEST_P(CordRepBtreeNavigatorTest, ReadBeyondLengthOfTree) {
+  CordRepBtreeNavigator nav;
+  nav.InitFirst(tree());
+  ReadResult result = nav.Read(2, tree()->length);
+  ASSERT_THAT(result.tree, Eq(nullptr));
+}
+
+}  // namespace
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.cc
new file mode 100644
index 00000000000..3ba43144ea9
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.cc
@@ -0,0 +1,68 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree_reader.h"
+
+#include <cassert>
+
+#include "absl/base/config.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_btree_navigator.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+absl::string_view CordRepBtreeReader::Read(size_t n, size_t chunk_size,
+                                           CordRep*& tree) {
+  assert(chunk_size <= navigator_.Current()->length);
+
+  // If chunk_size is non-zero, we need to start inside last returned edge.
+  // Else we start reading at the next data edge of the tree.
+  CordRep* edge = chunk_size ? navigator_.Current() : navigator_.Next();
+  const size_t offset = chunk_size ? edge->length - chunk_size : 0;
+
+  // Read the sub tree and verify we got what we wanted.
+  ReadResult result = navigator_.Read(offset, n);
+  tree = result.tree;
+
+  // If the data returned in `tree` was covered entirely by `chunk_size`, i.e.,
+  // read from the 'previous' edge, we did not consume any additional data, and
+  // can directly return the substring into the current data edge as the next
+  // chunk. We can easily establish from the above code that `navigator_.Next()`
+  // has not been called as that requires `chunk_size` to be zero.
+  if (n < chunk_size) return CordRepBtree::EdgeData(edge).substr(result.n);
+
+  // The amount of data taken from the last edge is `chunk_size` and `result.n`
+  // contains the offset into the current edge trailing the read data (which can
+  // be 0). As the call to `navigator_.Read()` could have consumed all remaining
+  // data, calling `navigator_.Current()` is not safe before checking if we
+  // already consumed all remaining data.
+  const size_t consumed_by_read = n - chunk_size - result.n;
+  if (consumed_ + consumed_by_read >= length()) {
+    consumed_ = length();
+    return {};
+  }
+
+  // We did not read all data, return remaining data from current edge.
+  edge = navigator_.Current();
+  consumed_ += consumed_by_read + edge->length;
+  return CordRepBtree::EdgeData(edge).substr(result.n);
+}
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.h
new file mode 100644
index 00000000000..c19fa43dd64
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader.h
@@ -0,0 +1,219 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_READER_H_
+#define ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_READER_H_
+
+#include <cassert>
+
+#include "absl/base/config.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_btree_navigator.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+// CordRepBtreeReader implements logic to iterate over cord btrees.
+// References to the underlying data are returned as absl::string_view values.
+// The most typical use case is a forward only iteration over tree data.
+// The class also provides `Skip()`, `Seek()` and `Read()` methods similar to
+// CordRepBtreeNavigator that allow more advanced navigation. The class provides
+// a `consumed` property which contains the end offset of the chunk last
+// returned to the user which is useful in cord iteration logic.
+//
+// Example: iterate over all data inside a cord btree:
+//
+//   CordRepBtreeReader reader;
+//   for (string_view sv = reader.Init(tree); !sv.Empty(); sv = sv.Next()) {
+//     DoSomethingWithDataIn(sv);
+//   }
+//
+// All navigation methods always return the next 'chunk' of data. The class
+// assumes that all data is directly 'consumed' by the caller. For example:
+// invoking `Skip()` will skip the desired number of bytes, and directly
+// read and return the next chunk of data directly after the skipped bytes.
+//
+// Example: iterate over all data inside a btree skipping the first 100 bytes:
+//
+//   CordRepBtreeReader reader;
+//   absl::string_view sv = reader.Init(tree);
+//   if (sv.length() > 100) {
+//     sv.RemovePrefix(100);
+//   } else {
+//     sv = reader.Skip(100 - sv.length());
+//   }
+//   while (!sv.empty()) {
+//     DoSomethingWithDataIn(sv);
+//     absl::string_view sv = reader.Next();
+//   }
+//
+// It is important to notice that `consumed` represents the end position of the
+// last data edge returned to the caller, not the cumulative data returned to
+// the caller which can be less in cases of skipping or seeking over data.
+//
+// For example, consider a cord btree with five data edges: "abc", "def", "ghi",
+// "jkl" and "mno":
+//
+//   absl::string_view sv;
+//   CordRepBtreeReader reader;
+//
+//   sv = reader.Init(tree); // sv = "abc", reader.consumed() = 3
+//   sv = reader.Skip(4);    // sv = "hi",  reader.consumed() = 9
+//   sv = reader.Skip(2);    // sv = "l",   reader.consumed() = 12
+//   sv = reader.Next();     // sv = "mno", reader.consumed() = 15
+//
+// In the above example, `reader.consumed()` reflects the data edges iterated
+// over or skipped by the reader, not the amount of data 'consumed' by the
+// caller.
+class CordRepBtreeReader {
+ public:
+  using ReadResult = CordRepBtreeNavigator::ReadResult;
+  using Position = CordRepBtreeNavigator::Position;
+
+  // Returns true if this instance is not empty.
+  explicit operator bool() const { return navigator_.btree() != nullptr; }
+
+  // Returns the tree referenced by this instance or nullptr if empty.
+  CordRepBtree* btree() const { return navigator_.btree(); }
+
+  // Returns the current data edge inside the referenced btree.
+  // Requires that the current instance is not empty.
+  CordRep* node() const { return navigator_.Current(); }
+
+  // Returns the length of the referenced tree.
+  // Requires that the current instance is not empty.
+  size_t length() const;
+
+  // Returns the end offset of the last navigated to chunk, which represents the
+  // total bytes 'consumed' relative to the start of the tree. The returned
+  // value is never zero. For example, initializing a reader with a tree with a
+  // first data edge of 19 bytes will return `consumed() = 19`. See also the
+  // class comments on the meaning of `consumed`.
+  // Requires that the current instance is not empty.
+  size_t consumed() const;
+
+  // Resets this instance to an empty value.
+  void Reset() { navigator_.Reset(); }
+
+  // Initializes this instance with `tree`. `tree` must not be null.
+  // Returns a reference to the first data edge of the provided tree.
+  absl::string_view Init(CordRepBtree* tree);
+
+  // Navigates to and returns the next data edge of the referenced tree.
+  // Returns an empty string_view if an attempt is made to read beyond the end
+  // of the tree, i.e.: if `remaining()` is zero indicating an EOF condition.
+  // Requires that the current instance is not empty.
+  absl::string_view Next();
+
+  // Skips the provided amount of bytes and returns a reference to the data
+  // directly following the skipped bytes.
+  absl::string_view Skip(size_t skip);
+
+  // Reads `n` bytes into `tree`.
+  // If `chunk_size` is zero, starts reading at the next data edge. If
+  // `chunk_size` is non zero, the read starts at the last `chunk_size` bytes of
+  // the last returned data edge. Effectively, this means that the read starts
+  // at offset `consumed() - chunk_size`.
+  // Requires that `chunk_size` is less than or equal to the length of the
+  // last returned data edge. The purpose of `chunk_size` is to simplify code
+  // partially consuming a returned chunk and wanting to include the remaining
+  // bytes in the Read call. For example, the below code will read 1000 bytes of
+  // data into a cord tree if the first chunk starts with "big:":
+  //
+  //   CordRepBtreeReader reader;
+  //   absl::string_view sv = reader.Init(tree);
+  //   if (absl::StartsWith(sv, "big:")) {
+  //     CordRepBtree tree;
+  //     sv = reader.Read(1000, sv.size() - 4 /* "big:" */, &tree);
+  //   }
+  //
+  // This method will return an empty string view if all remaining data was
+  // read. If `n` exceeded the amount of remaining data this function will
+  // return an empty string view and `tree` will be set to nullptr.
+  // In both cases, `consumed` will be set to `length`.
+  absl::string_view Read(size_t n, size_t chunk_size, CordRep*& tree);
+
+  // Navigates to the chunk at offset `offset`.
+  // Returns a reference into the navigated to chunk, adjusted for the relative
+  // position of `offset` into that chunk. For example, calling `Seek(13)` on a
+  // cord tree containing 2 chunks of 10 and 20 bytes respectively will return
+  // a string view into the second chunk starting at offset 3 with a size of 17.
+  // Returns an empty string view if `offset` is equal to or greater than the
+  // length of the referenced tree.
+  absl::string_view Seek(size_t offset);
+
+ private:
+  size_t consumed_;
+  CordRepBtreeNavigator navigator_;
+};
+
+inline size_t CordRepBtreeReader::length() const {
+  assert(btree() != nullptr);
+  return btree()->length;
+}
+
+inline size_t CordRepBtreeReader::consumed() const {
+  assert(btree() != nullptr);
+  return consumed_;
+}
+
+inline absl::string_view CordRepBtreeReader::Init(CordRepBtree* tree) {
+  assert(tree != nullptr);
+  const CordRep* edge = navigator_.InitFirst(tree);
+  consumed_ = edge->length;
+  return CordRepBtree::EdgeData(edge);
+}
+
+inline absl::string_view CordRepBtreeReader::Next() {
+  assert(consumed() < length());
+  const CordRep* edge = navigator_.Next();
+  assert(edge != nullptr);
+  consumed_ += edge->length;
+  return CordRepBtree::EdgeData(edge);
+}
+
+inline absl::string_view CordRepBtreeReader::Skip(size_t skip) {
+  // As we are always positioned on the last 'consumed' edge, we
+  // need to skip the current edge as well as `skip`.
+  const size_t edge_length = navigator_.Current()->length;
+  CordRepBtreeNavigator::Position pos = navigator_.Skip(skip + edge_length);
+  if (ABSL_PREDICT_FALSE(pos.edge == nullptr)) {
+    consumed_ = length();
+    return {};
+  }
+  // The combined length of all edges skipped before `pos.edge` is `skip -
+  // pos.offset`, all of which are 'consumed', as well as the current edge.
+  consumed_ += skip - pos.offset + pos.edge->length;
+  return CordRepBtree::EdgeData(pos.edge).substr(pos.offset);
+}
+
+inline absl::string_view CordRepBtreeReader::Seek(size_t offset) {
+  const CordRepBtreeNavigator::Position pos = navigator_.Seek(offset);
+  if (ABSL_PREDICT_FALSE(pos.edge == nullptr)) {
+    consumed_ = length();
+    return {};
+  }
+  absl::string_view chunk = CordRepBtree::EdgeData(pos.edge).substr(pos.offset);
+  consumed_ = offset + chunk.length();
+  return chunk;
+}
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_READER_H_
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc
new file mode 100644
index 00000000000..44d3365f13f
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc
@@ -0,0 +1,285 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree_reader.h"
+
+#include <iostream>
+#include <random>
+#include <string>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/cord.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_test_util.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+namespace {
+
+using ::testing::Eq;
+using ::testing::IsEmpty;
+using ::testing::Ne;
+using ::testing::Not;
+
+using ::absl::cordrep_testing::CordRepBtreeFromFlats;
+using ::absl::cordrep_testing::MakeFlat;
+using ::absl::cordrep_testing::CordToString;
+using ::absl::cordrep_testing::CreateFlatsFromString;
+using ::absl::cordrep_testing::CreateRandomString;
+
+using ReadResult = CordRepBtreeReader::ReadResult;
+
+TEST(CordRepBtreeReaderTest, Next) {
+  constexpr size_t kChars = 3;
+  const size_t cap = CordRepBtree::kMaxCapacity;
+  int counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17};
+
+  for (int count : counts) {
+    std::string data = CreateRandomString(count * kChars);
+    std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars);
+    CordRepBtree* node = CordRepBtreeFromFlats(flats);
+
+    CordRepBtreeReader reader;
+    absl::string_view chunk = reader.Init(node);
+    EXPECT_THAT(chunk, Eq(data.substr(0, chunk.length())));
+
+    size_t consumed = chunk.length();
+    EXPECT_THAT(reader.consumed(), Eq(consumed));
+
+    while (consumed < data.length()) {
+      chunk = reader.Next();
+      EXPECT_THAT(chunk, Eq(data.substr(consumed, chunk.length())));
+
+      consumed += chunk.length();
+      EXPECT_THAT(reader.consumed(), Eq(consumed));
+    }
+
+    EXPECT_THAT(consumed, Eq(data.length()));
+    EXPECT_THAT(reader.consumed(), Eq(data.length()));
+
+    CordRep::Unref(node);
+  }
+}
+
+TEST(CordRepBtreeReaderTest, Skip) {
+  constexpr size_t kChars = 3;
+  const size_t cap = CordRepBtree::kMaxCapacity;
+  int counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17};
+
+  for (int count : counts) {
+    std::string data = CreateRandomString(count * kChars);
+    std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars);
+    CordRepBtree* node = CordRepBtreeFromFlats(flats);
+
+    for (size_t skip1 = 0; skip1 < data.length() - kChars; ++skip1) {
+      for (size_t skip2 = 0; skip2 < data.length() - kChars; ++skip2) {
+        CordRepBtreeReader reader;
+        absl::string_view chunk = reader.Init(node);
+        size_t consumed = chunk.length();
+
+        chunk = reader.Skip(skip1);
+        ASSERT_THAT(chunk, Eq(data.substr(consumed + skip1, chunk.length())));
+        consumed += chunk.length() + skip1;
+        ASSERT_THAT(reader.consumed(), Eq(consumed));
+
+        if (consumed >= data.length()) continue;
+
+        size_t skip = std::min(data.length() - consumed - 1, skip2);
+        chunk = reader.Skip(skip);
+        ASSERT_THAT(chunk, Eq(data.substr(consumed + skip, chunk.length())));
+      }
+    }
+
+    CordRep::Unref(node);
+  }
+}
+
+TEST(CordRepBtreeReaderTest, SkipBeyondLength) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc"));
+  tree = CordRepBtree::Append(tree, MakeFlat("def"));
+  CordRepBtreeReader reader;
+  reader.Init(tree);
+  EXPECT_THAT(reader.Skip(100), IsEmpty());
+  EXPECT_THAT(reader.consumed(), Eq(6));
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeReaderTest, Seek) {
+  constexpr size_t kChars = 3;
+  const size_t cap = CordRepBtree::kMaxCapacity;
+  int counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17};
+
+  for (int count : counts) {
+    std::string data = CreateRandomString(count * kChars);
+    std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars);
+    CordRepBtree* node = CordRepBtreeFromFlats(flats);
+
+    for (size_t seek = 0; seek < data.length() - 1; ++seek) {
+      CordRepBtreeReader reader;
+      reader.Init(node);
+      absl::string_view chunk = reader.Seek(seek);
+      ASSERT_THAT(chunk, Not(IsEmpty()));
+      ASSERT_THAT(chunk, Eq(data.substr(seek, chunk.length())));
+      ASSERT_THAT(reader.consumed(), Eq(seek + chunk.length()));
+    }
+
+    CordRep::Unref(node);
+  }
+}
+
+TEST(CordRepBtreeReaderTest, SeekBeyondLength) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc"));
+  tree = CordRepBtree::Append(tree, MakeFlat("def"));
+  CordRepBtreeReader reader;
+  reader.Init(tree);
+  EXPECT_THAT(reader.Seek(6), IsEmpty());
+  EXPECT_THAT(reader.consumed(), Eq(6));
+  EXPECT_THAT(reader.Seek(100), IsEmpty());
+  EXPECT_THAT(reader.consumed(), Eq(6));
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeReaderTest, Read) {
+  std::string data = "abcdefghijklmno";
+  std::vector<CordRep*> flats = CreateFlatsFromString(data, 5);
+  CordRepBtree* node = CordRepBtreeFromFlats(flats);
+
+  CordRep* tree;
+  CordRepBtreeReader reader;
+  absl::string_view chunk;
+
+  // Read zero bytes
+  chunk = reader.Init(node);
+  chunk = reader.Read(0, chunk.length(), tree);
+  EXPECT_THAT(tree, Eq(nullptr));
+  EXPECT_THAT(chunk, Eq("abcde"));
+  EXPECT_THAT(reader.consumed(), Eq(5));
+  EXPECT_THAT(reader.Next(), Eq("fghij"));
+
+  // Read in full
+  chunk = reader.Init(node);
+  chunk = reader.Read(15, chunk.length(), tree);
+  EXPECT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("abcdefghijklmno"));
+  EXPECT_THAT(chunk, Eq(""));
+  EXPECT_THAT(reader.consumed(), Eq(15));
+  CordRep::Unref(tree);
+
+  // Read < chunk bytes
+  chunk = reader.Init(node);
+  chunk = reader.Read(3, chunk.length(), tree);
+  ASSERT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("abc"));
+  EXPECT_THAT(chunk, Eq("de"));
+  EXPECT_THAT(reader.consumed(), Eq(5));
+  EXPECT_THAT(reader.Next(), Eq("fghij"));
+  CordRep::Unref(tree);
+
+  // Read < chunk bytes at offset
+  chunk = reader.Init(node);
+  chunk = reader.Read(2, chunk.length() - 2, tree);
+  ASSERT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("cd"));
+  EXPECT_THAT(chunk, Eq("e"));
+  EXPECT_THAT(reader.consumed(), Eq(5));
+  EXPECT_THAT(reader.Next(), Eq("fghij"));
+  CordRep::Unref(tree);
+
+  // Read from consumed chunk
+  chunk = reader.Init(node);
+  chunk = reader.Read(3, 0, tree);
+  ASSERT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("fgh"));
+  EXPECT_THAT(chunk, Eq("ij"));
+  EXPECT_THAT(reader.consumed(), Eq(10));
+  EXPECT_THAT(reader.Next(), Eq("klmno"));
+  CordRep::Unref(tree);
+
+  // Read across chunks
+  chunk = reader.Init(node);
+  chunk = reader.Read(12, chunk.length() - 2, tree);
+  ASSERT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("cdefghijklmn"));
+  EXPECT_THAT(chunk, Eq("o"));
+  EXPECT_THAT(reader.consumed(), Eq(15));
+  CordRep::Unref(tree);
+
+  // Read across chunks landing on exact edge boundary
+  chunk = reader.Init(node);
+  chunk = reader.Read(10 - 2, chunk.length() - 2, tree);
+  ASSERT_THAT(tree, Ne(nullptr));
+  EXPECT_THAT(CordToString(tree), Eq("cdefghij"));
+  EXPECT_THAT(chunk, Eq("klmno"));
+  EXPECT_THAT(reader.consumed(), Eq(15));
+  CordRep::Unref(tree);
+
+  CordRep::Unref(node);
+}
+
+TEST(CordRepBtreeReaderTest, ReadExhaustive) {
+  constexpr size_t kChars = 3;
+  const size_t cap = CordRepBtree::kMaxCapacity;
+  int counts[] = {1, 2, cap, cap * cap + 1, cap * cap * cap * 2 + 17};
+
+  for (int count : counts) {
+    std::string data = CreateRandomString(count * kChars);
+    std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars);
+    CordRepBtree* node = CordRepBtreeFromFlats(flats);
+
+    for (size_t read_size : {kChars - 1, kChars, kChars + 7, cap * cap}) {
+      CordRepBtreeReader reader;
+      absl::string_view chunk = reader.Init(node);
+
+      // `consumed` tracks the end of last consumed chunk which is the start of
+      // the next chunk: we always read with `chunk_size = chunk.length()`.
+      size_t consumed = 0;
+      size_t remaining = data.length();
+      while (remaining > 0) {
+        CordRep* tree;
+        size_t n = (std::min)(remaining, read_size);
+        chunk = reader.Read(n, chunk.length(), tree);
+        EXPECT_THAT(tree, Ne(nullptr));
+        if (tree) {
+          EXPECT_THAT(CordToString(tree), Eq(data.substr(consumed, n)));
+          CordRep::Unref(tree);
+        }
+
+        consumed += n;
+        remaining -= n;
+        EXPECT_THAT(reader.consumed(), Eq(consumed + chunk.length()));
+
+        if (remaining > 0) {
+          ASSERT_FALSE(chunk.empty());
+          ASSERT_THAT(chunk, Eq(data.substr(consumed, chunk.length())));
+        } else {
+          ASSERT_TRUE(chunk.empty()) << chunk;
+        }
+      }
+    }
+
+    CordRep::Unref(node);
+  }
+}
+
+}  // namespace
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_test.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_test.cc
new file mode 100644
index 00000000000..073a7d45a99
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_test.cc
@@ -0,0 +1,1395 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_btree.h"
+
+#include <cmath>
+#include <deque>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/cleanup/cleanup.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_test_util.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+class CordRepBtreeTestPeer {
+ public:
+  static void SetEdge(CordRepBtree* node, size_t idx, CordRep* edge) {
+    node->edges_[idx] = edge;
+  }
+  static void AddEdge(CordRepBtree* node, CordRep* edge) {
+    node->edges_[node->fetch_add_end(1)] = edge;
+  }
+};
+
+namespace {
+
+using ::absl::cordrep_testing::AutoUnref;
+using ::absl::cordrep_testing::CordToString;
+using ::absl::cordrep_testing::CreateFlatsFromString;
+using ::absl::cordrep_testing::CreateRandomString;
+using ::absl::cordrep_testing::MakeConcat;
+using ::absl::cordrep_testing::MakeExternal;
+using ::absl::cordrep_testing::MakeFlat;
+using ::absl::cordrep_testing::MakeSubstring;
+using ::testing::_;
+using ::testing::AllOf;
+using ::testing::AnyOf;
+using ::testing::Conditional;
+using ::testing::ElementsAre;
+using ::testing::ElementsAreArray;
+using ::testing::Eq;
+using ::testing::HasSubstr;
+using ::testing::Ne;
+using ::testing::Not;
+using ::testing::SizeIs;
+using ::testing::TypedEq;
+
+MATCHER_P(EqFlatHolding, data, "Equals flat holding data") {
+  if (arg->tag < FLAT) {
+    *result_listener << "Expected FLAT, got tag " << static_cast<int>(arg->tag);
+    return false;
+  }
+  std::string actual = CordToString(arg);
+  if (actual != data) {
+    *result_listener << "Expected flat holding \"" << data
+                     << "\", got flat holding \"" << actual << "\"";
+    return false;
+  }
+  return true;
+}
+
+MATCHER_P(IsNode, height, absl::StrCat("Is a valid node of height ", height)) {
+  if (arg == nullptr) {
+    *result_listener << "Expected NODE, got nullptr";
+    return false;
+  }
+  if (arg->tag != BTREE) {
+    *result_listener << "Expected NODE, got " << static_cast<int>(arg->tag);
+    return false;
+  }
+  if (!CordRepBtree::IsValid(arg->btree())) {
+    CordRepBtree::Dump(arg->btree(), "Expected valid NODE, got:", false,
+                       *result_listener->stream());
+    return false;
+  }
+  if (arg->btree()->height() != height) {
+    *result_listener << "Expected NODE of height " << height << ", got "
+                     << arg->btree()->height();
+    return false;
+  }
+  return true;
+}
+
+MATCHER_P2(IsSubstring, start, length,
+           absl::StrCat("Is a substring(start = ", start, ", length = ", length,
+                        ")")) {
+  if (arg == nullptr) {
+    *result_listener << "Expected substring, got nullptr";
+    return false;
+  }
+  if (arg->tag != SUBSTRING) {
+    *result_listener << "Expected SUBSTRING, got "
+                     << static_cast<int>(arg->tag);
+    return false;
+  }
+  const CordRepSubstring* const substr = arg->substring();
+  if (substr->start != start || substr->length != length) {
+    *result_listener << "Expected substring(" << start << ", " << length
+                     << "), got substring(" << substr->start << ", "
+                     << substr->length << ")";
+    return false;
+  }
+  return true;
+}
+
+// DataConsumer is a simple helper class used by tests to 'consume' string
+// fragments from the provided input in forward or backward direction.
+class DataConsumer {
+ public:
+  // Starts consumption of `data`. Caller must make sure `data` outlives this
+  // instance. Consumes data starting at the front if `forward` is true, else
+  // consumes data from the back.
+  DataConsumer(absl::string_view data, bool forward)
+      : data_(data), forward_(forward) {}
+
+  // Return the next `n` bytes from referenced data.
+  absl::string_view Next(size_t n) {
+    assert(n <= data_.size() - consumed_);
+    consumed_ += n;
+    return data_.substr(forward_ ? consumed_ - n : data_.size() - consumed_, n);
+  }
+
+  // Returns all data consumed so far.
+  absl::string_view Consumed() const {
+    return forward_ ? data_.substr(0, consumed_)
+                    : data_.substr(data_.size() - consumed_);
+  }
+
+ private:
+  absl::string_view data_;
+  size_t consumed_ = 0;
+  bool forward_;
+};
+
+// BtreeAdd returns either CordRepBtree::Append or CordRepBtree::Prepend.
+CordRepBtree* BtreeAdd(CordRepBtree* node, bool append,
+                       absl::string_view data) {
+  return append ? CordRepBtree::Append(node, data)
+                : CordRepBtree::Prepend(node, data);
+}
+
+// Recursively collects all leaf edges from `tree` and appends them to `edges`.
+void GetLeafEdges(const CordRepBtree* tree, std::vector<CordRep*>& edges) {
+  if (tree->height() == 0) {
+    for (CordRep* edge : tree->Edges()) {
+      edges.push_back(edge);
+    }
+  } else {
+    for (CordRep* edge : tree->Edges()) {
+      GetLeafEdges(edge->btree(), edges);
+    }
+  }
+}
+
+// Recursively collects and returns all leaf edges from `tree`.
+std::vector<CordRep*> GetLeafEdges(const CordRepBtree* tree) {
+  std::vector<CordRep*> edges;
+  GetLeafEdges(tree, edges);
+  return edges;
+}
+
+// Creates a flat containing the hexadecimal value of `i` zero padded
+// to at least 4 digits prefixed with "0x", e.g.: "0x04AC".
+CordRepFlat* MakeHexFlat(size_t i) {
+  return MakeFlat(absl::StrCat("0x", absl::Hex(i, absl::kZeroPad4)));
+}
+
+CordRepBtree* MakeLeaf(size_t size = CordRepBtree::kMaxCapacity) {
+  assert(size <= CordRepBtree::kMaxCapacity);
+  CordRepBtree* leaf = CordRepBtree::Create(MakeHexFlat(0));
+  for (size_t i = 1; i < size; ++i) {
+    leaf = CordRepBtree::Append(leaf, MakeHexFlat(i));
+  }
+  return leaf;
+}
+
+CordRepBtree* MakeTree(size_t size, bool append = true) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeHexFlat(0));
+  for (size_t i = 1; i < size; ++i) {
+    tree = append ? CordRepBtree::Append(tree, MakeHexFlat(i))
+                  : CordRepBtree::Prepend(tree, MakeHexFlat(i));
+  }
+  return tree;
+}
+
+CordRepBtree* CreateTree(absl::string_view data, size_t chunk_size) {
+  std::vector<CordRep*> flats = CreateFlatsFromString(data, chunk_size);
+  auto it = flats.begin();
+  CordRepBtree* tree = CordRepBtree::Create(*it);
+  while (++it != flats.end()) tree = CordRepBtree::Append(tree, *it);
+  return tree;
+}
+
+CordRepBtree* CreateTreeReverse(absl::string_view data, size_t chunk_size) {
+  std::vector<CordRep*> flats = CreateFlatsFromString(data, chunk_size);
+  auto rit = flats.rbegin();
+  CordRepBtree* tree = CordRepBtree::Create(*rit);
+  while (++rit != flats.rend()) tree = CordRepBtree::Prepend(tree, *rit);
+  return tree;
+}
+
+class CordRepBtreeTest : public testing::TestWithParam<bool> {
+ public:
+  bool shared() const { return GetParam(); }
+
+  static std::string ToString(testing::TestParamInfo<bool> param) {
+    return param.param ? "Shared" : "Private";
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(WithParam, CordRepBtreeTest, testing::Bool(),
+                         CordRepBtreeTest::ToString);
+
+class CordRepBtreeHeightTest : public testing::TestWithParam<int> {
+ public:
+  int height() const { return GetParam(); }
+
+  static std::string ToString(testing::TestParamInfo<int> param) {
+    return absl::StrCat(param.param);
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(WithHeights, CordRepBtreeHeightTest,
+                         testing::Range(0, CordRepBtree::kMaxHeight),
+                         CordRepBtreeHeightTest::ToString);
+
+using TwoBools = testing::tuple<bool, bool>;
+
+class CordRepBtreeDualTest : public testing::TestWithParam<TwoBools> {
+ public:
+  bool first_shared() const { return std::get<0>(GetParam()); }
+  bool second_shared() const { return std::get<1>(GetParam()); }
+
+  static std::string ToString(testing::TestParamInfo<TwoBools> param) {
+    if (std::get<0>(param.param)) {
+      return std::get<1>(param.param) ? "BothShared" : "FirstShared";
+    }
+    return std::get<1>(param.param) ? "SecondShared" : "Private";
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(WithParam, CordRepBtreeDualTest,
+                         testing::Combine(testing::Bool(), testing::Bool()),
+                         CordRepBtreeDualTest::ToString);
+
+TEST(CordRepBtreeTest, SizeIsMultipleOf64) {
+  // Only enforce for fully 64-bit platforms.
+  if (sizeof(size_t) == 8 && sizeof(void*) == 8) {
+    EXPECT_THAT(sizeof(CordRepBtree) % 64, Eq(0)) << "Should be multiple of 64";
+  }
+}
+
+TEST(CordRepBtreeTest, NewDestroyEmptyTree) {
+  auto* tree = CordRepBtree::New();
+  EXPECT_THAT(tree->size(), Eq(0));
+  EXPECT_THAT(tree->height(), Eq(0));
+  EXPECT_THAT(tree->Edges(), ElementsAre());
+  CordRepBtree::Destroy(tree);
+}
+
+TEST(CordRepBtreeTest, NewDestroyEmptyTreeAtHeight) {
+  auto* tree = CordRepBtree::New(3);
+  EXPECT_THAT(tree->size(), Eq(0));
+  EXPECT_THAT(tree->height(), Eq(3));
+  EXPECT_THAT(tree->Edges(), ElementsAre());
+  CordRepBtree::Destroy(tree);
+}
+
+TEST(CordRepBtreeTest, Btree) {
+  CordRep* rep = CordRepBtree::New();
+  EXPECT_THAT(rep->btree(), Eq(rep));
+  EXPECT_THAT(static_cast<const CordRep*>(rep)->btree(), Eq(rep));
+  CordRep::Unref(rep);
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+  rep = MakeFlat("Hello world");
+  EXPECT_DEATH(rep->btree(), ".*");
+  EXPECT_DEATH(static_cast<const CordRep*>(rep)->btree(), ".*");
+  CordRep::Unref(rep);
+#endif
+}
+
+TEST(CordRepBtreeTest, EdgeData) {
+  CordRepFlat* flat = MakeFlat("Hello world");
+  CordRepExternal* external = MakeExternal("Hello external");
+  CordRep* substr1 = MakeSubstring(1, 6, CordRep::Ref(flat));
+  CordRep* substr2 = MakeSubstring(1, 6, CordRep::Ref(external));
+  CordRep* concat = MakeConcat(CordRep::Ref(flat), CordRep::Ref(external));
+  CordRep* bad_substr = MakeSubstring(1, 2, CordRep::Ref(substr1));
+
+  EXPECT_TRUE(CordRepBtree::IsDataEdge(flat));
+  EXPECT_THAT(CordRepBtree::EdgeDataPtr(flat),
+              TypedEq<const void*>(flat->Data()));
+  EXPECT_THAT(CordRepBtree::EdgeData(flat), Eq("Hello world"));
+
+  EXPECT_TRUE(CordRepBtree::IsDataEdge(external));
+  EXPECT_THAT(CordRepBtree::EdgeDataPtr(external),
+              TypedEq<const void*>(external->base));
+  EXPECT_THAT(CordRepBtree::EdgeData(external), Eq("Hello external"));
+
+  EXPECT_TRUE(CordRepBtree::IsDataEdge(substr1));
+  EXPECT_THAT(CordRepBtree::EdgeDataPtr(substr1),
+              TypedEq<const void*>(flat->Data() + 1));
+  EXPECT_THAT(CordRepBtree::EdgeData(substr1), Eq("ello w"));
+
+  EXPECT_TRUE(CordRepBtree::IsDataEdge(substr2));
+  EXPECT_THAT(CordRepBtree::EdgeDataPtr(substr2),
+              TypedEq<const void*>(external->base + 1));
+  EXPECT_THAT(CordRepBtree::EdgeData(substr2), Eq("ello e"));
+
+  EXPECT_FALSE(CordRepBtree::IsDataEdge(concat));
+  EXPECT_FALSE(CordRepBtree::IsDataEdge(bad_substr));
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+  EXPECT_DEATH(CordRepBtree::EdgeData(concat), ".*");
+  EXPECT_DEATH(CordRepBtree::EdgeDataPtr(concat), ".*");
+  EXPECT_DEATH(CordRepBtree::EdgeData(bad_substr), ".*");
+  EXPECT_DEATH(CordRepBtree::EdgeDataPtr(bad_substr), ".*");
+#endif
+
+  CordRep::Unref(bad_substr);
+  CordRep::Unref(concat);
+  CordRep::Unref(substr2);
+  CordRep::Unref(substr1);
+  CordRep::Unref(external);
+  CordRep::Unref(flat);
+}
+
+TEST(CordRepBtreeTest, CreateUnrefLeaf) {
+  auto* flat = MakeFlat("a");
+  auto* leaf = CordRepBtree::Create(flat);
+  EXPECT_THAT(leaf->size(), Eq(1));
+  EXPECT_THAT(leaf->height(), Eq(0));
+  EXPECT_THAT(leaf->Edges(), ElementsAre(flat));
+  CordRepBtree::Unref(leaf);
+}
+
+TEST(CordRepBtreeTest, NewUnrefNode) {
+  auto* leaf = CordRepBtree::Create(MakeFlat("a"));
+  CordRepBtree* tree = CordRepBtree::New(leaf);
+  EXPECT_THAT(tree->size(), Eq(1));
+  EXPECT_THAT(tree->height(), Eq(1));
+  EXPECT_THAT(tree->Edges(), ElementsAre(leaf));
+  CordRepBtree::Unref(tree);
+}
+
+TEST_P(CordRepBtreeTest, AppendToLeafToCapacity) {
+  AutoUnref refs;
+  std::vector<CordRep*> flats;
+  flats.push_back(MakeHexFlat(0));
+  auto* leaf = CordRepBtree::Create(flats.back());
+
+  for (size_t i = 1; i < CordRepBtree::kMaxCapacity; ++i) {
+    refs.RefIf(shared(), leaf);
+    flats.push_back(MakeHexFlat(i));
+    auto* result = CordRepBtree::Append(leaf, flats.back());
+    EXPECT_THAT(result->height(), Eq(0));
+    EXPECT_THAT(result, Conditional(shared(), Ne(leaf), Eq(leaf)));
+    EXPECT_THAT(result->Edges(), ElementsAreArray(flats));
+    leaf = result;
+  }
+  CordRep::Unref(leaf);
+}
+
+TEST_P(CordRepBtreeTest, PrependToLeafToCapacity) {
+  AutoUnref refs;
+  std::deque<CordRep*> flats;
+  flats.push_front(MakeHexFlat(0));
+  auto* leaf = CordRepBtree::Create(flats.front());
+
+  for (size_t i = 1; i < CordRepBtree::kMaxCapacity; ++i) {
+    refs.RefIf(shared(), leaf);
+    flats.push_front(MakeHexFlat(i));
+    auto* result = CordRepBtree::Prepend(leaf, flats.front());
+    EXPECT_THAT(result->height(), Eq(0));
+    EXPECT_THAT(result, Conditional(shared(), Ne(leaf), Eq(leaf)));
+    EXPECT_THAT(result->Edges(), ElementsAreArray(flats));
+    leaf = result;
+  }
+  CordRep::Unref(leaf);
+}
+
+// This test specifically aims at code aligning data at either the front or the
+// back of the contained `edges[]` array, alternating Append and Prepend will
+// move `begin()` and `end()` values as needed for each added value.
+TEST_P(CordRepBtreeTest, AppendPrependToLeafToCapacity) {
+  AutoUnref refs;
+  std::deque<CordRep*> flats;
+  flats.push_front(MakeHexFlat(0));
+  auto* leaf = CordRepBtree::Create(flats.front());
+
+  for (size_t i = 1; i < CordRepBtree::kMaxCapacity; ++i) {
+    refs.RefIf(shared(), leaf);
+    CordRepBtree* result;
+    if (i % 2 != 0) {
+      flats.push_front(MakeHexFlat(i));
+      result = CordRepBtree::Prepend(leaf, flats.front());
+    } else {
+      flats.push_back(MakeHexFlat(i));
+      result = CordRepBtree::Append(leaf, flats.back());
+    }
+    EXPECT_THAT(result->height(), Eq(0));
+    EXPECT_THAT(result, Conditional(shared(), Ne(leaf), Eq(leaf)));
+    EXPECT_THAT(result->Edges(), ElementsAreArray(flats));
+    leaf = result;
+  }
+  CordRep::Unref(leaf);
+}
+
+TEST_P(CordRepBtreeTest, AppendToLeafBeyondCapacity) {
+  AutoUnref refs;
+  auto* leaf = MakeLeaf();
+  refs.RefIf(shared(), leaf);
+  CordRep* flat = MakeFlat("abc");
+  auto* result = CordRepBtree::Append(leaf, flat);
+  ASSERT_THAT(result, IsNode(1));
+  EXPECT_THAT(result, Ne(leaf));
+  absl::Span<CordRep* const> edges = result->Edges();
+  ASSERT_THAT(edges, ElementsAre(leaf, IsNode(0)));
+  EXPECT_THAT(edges[1]->btree()->Edges(), ElementsAre(flat));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, PrependToLeafBeyondCapacity) {
+  AutoUnref refs;
+  auto* leaf = MakeLeaf();
+  refs.RefIf(shared(), leaf);
+  CordRep* flat = MakeFlat("abc");
+  auto* result = CordRepBtree::Prepend(leaf, flat);
+  ASSERT_THAT(result, IsNode(1));
+  EXPECT_THAT(result, Ne(leaf));
+  absl::Span<CordRep* const> edges = result->Edges();
+  ASSERT_THAT(edges, ElementsAre(IsNode(0), leaf));
+  EXPECT_THAT(edges[0]->btree()->Edges(), ElementsAre(flat));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, AppendToTreeOneDeep) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  AutoUnref refs;
+  std::vector<CordRep*> flats;
+  flats.push_back(MakeHexFlat(0));
+  CordRepBtree* tree = CordRepBtree::Create(flats.back());
+  for (size_t i = 1; i <= max_cap; ++i) {
+    flats.push_back(MakeHexFlat(i));
+    tree = CordRepBtree::Append(tree, flats.back());
+  }
+  ASSERT_THAT(tree, IsNode(1));
+
+  for (size_t i = max_cap + 1; i < max_cap * max_cap; ++i) {
+    // Ref top level tree based on param.
+    // Ref leaf node once every 4 iterations, which should not have an
+    // observable effect other than that the leaf itself is copied.
+    refs.RefIf(shared(), tree);
+    refs.RefIf(i % 4 == 0, tree->Edges().back());
+
+    flats.push_back(MakeHexFlat(i));
+    CordRepBtree* result = CordRepBtree::Append(tree, flats.back());
+    ASSERT_THAT(result, IsNode(1));
+    ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+    std::vector<CordRep*> edges = GetLeafEdges(result);
+    ASSERT_THAT(edges, ElementsAreArray(flats));
+    tree = result;
+  }
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeTest, AppendToTreeTwoDeep) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  AutoUnref refs;
+  std::vector<CordRep*> flats;
+  flats.push_back(MakeHexFlat(0));
+  CordRepBtree* tree = CordRepBtree::Create(flats.back());
+  for (size_t i = 1; i <= max_cap * max_cap; ++i) {
+    flats.push_back(MakeHexFlat(i));
+    tree = CordRepBtree::Append(tree, flats.back());
+  }
+  ASSERT_THAT(tree, IsNode(2));
+  for (size_t i = max_cap * max_cap + 1; i < max_cap * max_cap * max_cap; ++i) {
+    // Ref top level tree based on param.
+    // Ref child node once every 16 iterations, and leaf node every 4
+    // iterrations which  which should not have an observable effect other than
+    //  the node and/or the leaf below it being copied.
+    refs.RefIf(shared(), tree);
+    refs.RefIf(i % 16 == 0, tree->Edges().back());
+    refs.RefIf(i % 4 == 0, tree->Edges().back()->btree()->Edges().back());
+
+    flats.push_back(MakeHexFlat(i));
+    CordRepBtree* result = CordRepBtree::Append(tree, flats.back());
+    ASSERT_THAT(result, IsNode(2));
+    ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+    std::vector<CordRep*> edges = GetLeafEdges(result);
+    ASSERT_THAT(edges, ElementsAreArray(flats));
+    tree = result;
+  }
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeTest, PrependToTreeOneDeep) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  AutoUnref refs;
+  std::deque<CordRep*> flats;
+  flats.push_back(MakeHexFlat(0));
+  CordRepBtree* tree = CordRepBtree::Create(flats.back());
+  for (size_t i = 1; i <= max_cap; ++i) {
+    flats.push_front(MakeHexFlat(i));
+    tree = CordRepBtree::Prepend(tree, flats.front());
+  }
+  ASSERT_THAT(tree, IsNode(1));
+
+  for (size_t i = max_cap + 1; i < max_cap * max_cap; ++i) {
+    // Ref top level tree based on param.
+    // Ref leaf node once every 4 iterations which should not have an observable
+    // effect other than than the leaf itself is copied.
+    refs.RefIf(shared(), tree);
+    refs.RefIf(i % 4 == 0, tree->Edges().back());
+
+    flats.push_front(MakeHexFlat(i));
+    CordRepBtree* result = CordRepBtree::Prepend(tree, flats.front());
+    ASSERT_THAT(result, IsNode(1));
+    ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+    std::vector<CordRep*> edges = GetLeafEdges(result);
+    ASSERT_THAT(edges, ElementsAreArray(flats));
+    tree = result;
+  }
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeTest, PrependToTreeTwoDeep) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  AutoUnref refs;
+  std::deque<CordRep*> flats;
+  flats.push_back(MakeHexFlat(0));
+  CordRepBtree* tree = CordRepBtree::Create(flats.back());
+  for (size_t i = 1; i <= max_cap * max_cap; ++i) {
+    flats.push_front(MakeHexFlat(i));
+    tree = CordRepBtree::Prepend(tree, flats.front());
+  }
+  ASSERT_THAT(tree, IsNode(2));
+  for (size_t i = max_cap * max_cap + 1; i < max_cap * max_cap * max_cap; ++i) {
+    // Ref top level tree based on param.
+    // Ref child node once every 16 iterations, and leaf node every 4
+    // iterrations which  which should not have an observable effect other than
+    //  the node and/or the leaf below it being copied.
+    refs.RefIf(shared(), tree);
+    refs.RefIf(i % 16 == 0, tree->Edges().back());
+    refs.RefIf(i % 4 == 0, tree->Edges().back()->btree()->Edges().back());
+
+    flats.push_front(MakeHexFlat(i));
+    CordRepBtree* result = CordRepBtree::Prepend(tree, flats.front());
+    ASSERT_THAT(result, IsNode(2));
+    ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+    std::vector<CordRep*> edges = GetLeafEdges(result);
+    ASSERT_THAT(edges, ElementsAreArray(flats));
+    tree = result;
+  }
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeDualTest, MergeLeafsNotExceedingCapacity) {
+  for (bool use_append : {false, true}) {
+    SCOPED_TRACE(use_append ? "Using Append" : "Using Prepend");
+
+    AutoUnref refs;
+    std::vector<CordRep*> flats;
+
+    // Build `left` side leaf appending all contained flats to `flats`
+    CordRepBtree* left = MakeLeaf(3);
+    GetLeafEdges(left, flats);
+    refs.RefIf(first_shared(), left);
+
+    // Build `right` side leaf appending all contained flats to `flats`
+    CordRepBtree* right = MakeLeaf(2);
+    GetLeafEdges(right, flats);
+    refs.RefIf(second_shared(), right);
+
+    CordRepBtree* tree = use_append ? CordRepBtree::Append(left, right)
+                                    : CordRepBtree::Prepend(right, left);
+    EXPECT_THAT(tree, IsNode(0));
+
+    // `tree` contains all flats originally belonging to `left` and `right`.
+    EXPECT_THAT(tree->Edges(), ElementsAreArray(flats));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+TEST_P(CordRepBtreeDualTest, MergeLeafsExceedingCapacity) {
+  for (bool use_append : {false, true}) {
+    SCOPED_TRACE(use_append ? "Using Append" : "Using Prepend");
+
+    AutoUnref refs;
+
+    // Build `left` side tree appending all contained flats to `flats`
+    CordRepBtree* left = MakeLeaf(CordRepBtree::kMaxCapacity - 2);
+    refs.RefIf(first_shared(), left);
+
+    // Build `right` side tree appending all contained flats to `flats`
+    CordRepBtree* right = MakeLeaf(CordRepBtree::kMaxCapacity - 1);
+    refs.RefIf(second_shared(), right);
+
+    CordRepBtree* tree = use_append ? CordRepBtree::Append(left, right)
+                                    : CordRepBtree::Prepend(right, left);
+    EXPECT_THAT(tree, IsNode(1));
+    EXPECT_THAT(tree->Edges(), ElementsAre(left, right));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+TEST_P(CordRepBtreeDualTest, MergeEqualHeightTrees) {
+  for (bool use_append : {false, true}) {
+    SCOPED_TRACE(use_append ? "Using Append" : "Using Prepend");
+
+    AutoUnref refs;
+    std::vector<CordRep*> flats;
+
+    // Build `left` side tree appending all contained flats to `flats`
+    CordRepBtree* left = MakeTree(CordRepBtree::kMaxCapacity * 3);
+    GetLeafEdges(left, flats);
+    refs.RefIf(first_shared(), left);
+
+    // Build `right` side tree appending all contained flats to `flats`
+    CordRepBtree* right = MakeTree(CordRepBtree::kMaxCapacity * 2);
+    GetLeafEdges(right, flats);
+    refs.RefIf(second_shared(), right);
+
+    CordRepBtree* tree = use_append ? CordRepBtree::Append(left, right)
+                                    : CordRepBtree::Prepend(right, left);
+    EXPECT_THAT(tree, IsNode(1));
+    EXPECT_THAT(tree->Edges(), SizeIs(5));
+
+    // `tree` contains all flats originally belonging to `left` and `right`.
+    EXPECT_THAT(GetLeafEdges(tree), ElementsAreArray(flats));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+TEST_P(CordRepBtreeDualTest, MergeLeafWithTreeNotExceedingLeafCapacity) {
+  for (bool use_append : {false, true}) {
+    SCOPED_TRACE(use_append ? "Using Append" : "Using Prepend");
+
+    AutoUnref refs;
+    std::vector<CordRep*> flats;
+
+    // Build `left` side tree appending all added flats to `flats`
+    CordRepBtree* left = MakeTree(CordRepBtree::kMaxCapacity * 2 + 2);
+    GetLeafEdges(left, flats);
+    refs.RefIf(first_shared(), left);
+
+    // Build `right` side tree appending all added flats to `flats`
+    CordRepBtree* right = MakeTree(3);
+    GetLeafEdges(right, flats);
+    refs.RefIf(second_shared(), right);
+
+    CordRepBtree* tree = use_append ? CordRepBtree::Append(left, right)
+                                    : CordRepBtree::Prepend(right, left);
+    EXPECT_THAT(tree, IsNode(1));
+    EXPECT_THAT(tree->Edges(), SizeIs(3));
+
+    // `tree` contains all flats originally belonging to `left` and `right`.
+    EXPECT_THAT(GetLeafEdges(tree), ElementsAreArray(flats));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+TEST_P(CordRepBtreeDualTest, MergeLeafWithTreeExceedingLeafCapacity) {
+  for (bool use_append : {false, true}) {
+    SCOPED_TRACE(use_append ? "Using Append" : "Using Prepend");
+
+    AutoUnref refs;
+    std::vector<CordRep*> flats;
+
+    // Build `left` side tree appending all added flats to `flats`
+    CordRepBtree* left = MakeTree(CordRepBtree::kMaxCapacity * 3 - 2);
+    GetLeafEdges(left, flats);
+    refs.RefIf(first_shared(), left);
+
+    // Build `right` side tree appending all added flats to `flats`
+    CordRepBtree* right = MakeTree(3);
+    GetLeafEdges(right, flats);
+    refs.RefIf(second_shared(), right);
+
+    CordRepBtree* tree = use_append ? CordRepBtree::Append(left, right)
+                                    : CordRepBtree::Prepend(right, left);
+    EXPECT_THAT(tree, IsNode(1));
+    EXPECT_THAT(tree->Edges(), SizeIs(4));
+
+    // `tree` contains all flats originally belonging to `left` and `right`.
+    EXPECT_THAT(GetLeafEdges(tree), ElementsAreArray(flats));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+void RefEdgesAt(size_t depth, AutoUnref& refs, CordRepBtree* tree) {
+  absl::Span<CordRep* const> edges = tree->Edges();
+  if (depth == 0) {
+    refs.Ref(edges.front());
+    refs.Ref(edges.back());
+  } else {
+    assert(tree->height() > 0);
+    RefEdgesAt(depth - 1, refs, edges.front()->btree());
+    RefEdgesAt(depth - 1, refs, edges.back()->btree());
+  }
+}
+
+TEST(CordRepBtreeTest, MergeFuzzTest) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  std::minstd_rand rnd;
+  std::uniform_int_distribution<int> coin_flip(0, 1);
+  std::uniform_int_distribution<int> dice_throw(1, 6);
+
+  auto random_leaf_count = [&]() {
+    std::uniform_int_distribution<int> dist_height(0, 3);
+    std::uniform_int_distribution<int> dist_leaf(0, max_cap - 1);
+    const size_t height = dist_height(rnd);
+    return (height ? pow(max_cap, height) : 0) + dist_leaf(rnd);
+  };
+
+  for (int i = 0; i < 10000; ++i) {
+    AutoUnref refs;
+    std::vector<CordRep*> flats;
+
+    CordRepBtree* left = MakeTree(random_leaf_count(), coin_flip(rnd));
+    GetLeafEdges(left, flats);
+    if (dice_throw(rnd) == 1) {
+      std::uniform_int_distribution<int> dist(0, left->height());
+      RefEdgesAt(dist(rnd), refs, left);
+    }
+
+    CordRepBtree* right = MakeTree(random_leaf_count(), coin_flip(rnd));
+    GetLeafEdges(right, flats);
+    if (dice_throw(rnd) == 1) {
+      std::uniform_int_distribution<int> dist(0, right->height());
+      RefEdgesAt(dist(rnd), refs, right);
+    }
+
+    CordRepBtree* tree = CordRepBtree::Append(left, right);
+    EXPECT_THAT(GetLeafEdges(tree), ElementsAreArray(flats));
+    CordRepBtree::Unref(tree);
+  }
+}
+
+TEST(CordRepBtreeTest, SubTree) {
+  // Create tree of at least 2 levels high
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  const size_t n = max_cap * max_cap * 2;
+  const std::string data = CreateRandomString(n * 3);
+  std::vector<CordRep*> flats;
+  for (absl::string_view s = data; !s.empty(); s.remove_prefix(3)) {
+    flats.push_back(MakeFlat(s.substr(0, 3)));
+  }
+  CordRepBtree* node = CordRepBtree::Create(CordRep::Ref(flats[0]));
+  for (size_t i = 1; i < flats.size(); ++i) {
+    node = CordRepBtree::Append(node, CordRep::Ref(flats[i]));
+  }
+
+  for (int offset = 0; offset < data.length(); ++offset) {
+    for (int length = 1; length <= data.length() - offset; ++length) {
+      CordRep* rep = node->SubTree(offset, length);
+      EXPECT_THAT(CordToString(rep), Eq(data.substr(offset, length)));
+      CordRep::Unref(rep);
+    }
+  }
+  CordRepBtree::Unref(node);
+  for (CordRep* rep : flats) {
+    CordRep::Unref(rep);
+  }
+}
+
+TEST(CordRepBtreeTest, SubTreeOnExistingSubstring) {
+  // This test verifies that a SubTree call on a pre-existing (large) substring
+  // adjusts the existing substring if not shared, and else rewrites the
+  // existing substring.
+  AutoUnref refs;
+  std::string data = CreateRandomString(1000);
+  CordRepBtree* leaf = CordRepBtree::Create(MakeFlat("abc"));
+  CordRep* flat = MakeFlat(data);
+  leaf = CordRepBtree::Append(leaf, flat);
+
+  // Setup tree containing substring.
+  CordRep* result = leaf->SubTree(0, 3 + 990);
+  ASSERT_THAT(result->tag, Eq(BTREE));
+  CordRep::Unref(leaf);
+  leaf = result->btree();
+  ASSERT_THAT(leaf->Edges(), ElementsAre(_, IsSubstring(0, 990)));
+  EXPECT_THAT(leaf->Edges()[1]->substring()->child, Eq(flat));
+
+  // Verify substring of substring.
+  result = leaf->SubTree(3 + 5, 970);
+  ASSERT_THAT(result, IsSubstring(5, 970));
+  EXPECT_THAT(result->substring()->child, Eq(flat));
+  CordRep::Unref(result);
+
+  CordRep::Unref(leaf);
+}
+
+TEST_P(CordRepBtreeTest, AddDataToLeaf) {
+  const size_t n = CordRepBtree::kMaxCapacity;
+  const std::string data = CreateRandomString(n * 3);
+
+  for (bool append : {true, false}) {
+    AutoUnref refs;
+    DataConsumer consumer(data, append);
+    SCOPED_TRACE(append ? "Append" : "Prepend");
+
+    CordRepBtree* leaf = CordRepBtree::Create(MakeFlat(consumer.Next(3)));
+    for (size_t i = 1; i < n; ++i) {
+      refs.RefIf(shared(), leaf);
+      CordRepBtree* result = BtreeAdd(leaf, append, consumer.Next(3));
+      EXPECT_THAT(result, Conditional(shared(), Ne(leaf), Eq(leaf)));
+      EXPECT_THAT(CordToString(result), Eq(consumer.Consumed()));
+      leaf = result;
+    }
+    CordRep::Unref(leaf);
+  }
+}
+
+TEST_P(CordRepBtreeTest, AppendDataToTree) {
+  AutoUnref refs;
+  size_t n = CordRepBtree::kMaxCapacity + CordRepBtree::kMaxCapacity / 2;
+  std::string data = CreateRandomString(n * 3);
+  CordRepBtree* tree = refs.RefIf(shared(), CreateTree(data, 3));
+  CordRepBtree* leaf0 = tree->Edges()[0]->btree();
+  CordRepBtree* leaf1 = tree->Edges()[1]->btree();
+  CordRepBtree* result = CordRepBtree::Append(tree, "123456789");
+  EXPECT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+  EXPECT_THAT(result->Edges(),
+              ElementsAre(leaf0, Conditional(shared(), Ne(leaf1), Eq(leaf1))));
+  EXPECT_THAT(CordToString(result), Eq(data + "123456789"));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, PrependDataToTree) {
+  AutoUnref refs;
+  size_t n = CordRepBtree::kMaxCapacity + CordRepBtree::kMaxCapacity / 2;
+  std::string data = CreateRandomString(n * 3);
+  CordRepBtree* tree = refs.RefIf(shared(), CreateTreeReverse(data, 3));
+  CordRepBtree* leaf0 = tree->Edges()[0]->btree();
+  CordRepBtree* leaf1 = tree->Edges()[1]->btree();
+  CordRepBtree* result = CordRepBtree::Prepend(tree, "123456789");
+  EXPECT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+  EXPECT_THAT(result->Edges(),
+              ElementsAre(Conditional(shared(), Ne(leaf0), Eq(leaf0)), leaf1));
+  EXPECT_THAT(CordToString(result), Eq("123456789" + data));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, AddDataToTreeThreeLevelsDeep) {
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  const size_t n = max_cap * max_cap * max_cap;
+  const std::string data = CreateRandomString(n * 3);
+
+  for (bool append : {true, false}) {
+    AutoUnref refs;
+    DataConsumer consumer(data, append);
+    SCOPED_TRACE(append ? "Append" : "Prepend");
+
+    // Fill leaf
+    CordRepBtree* tree = CordRepBtree::Create(MakeFlat(consumer.Next(3)));
+    for (size_t i = 1; i < max_cap; ++i) {
+      tree = BtreeAdd(tree, append, consumer.Next(3));
+    }
+    ASSERT_THAT(CordToString(tree), Eq(consumer.Consumed()));
+
+    // Fill to maximum at one deep
+    refs.RefIf(shared(), tree);
+    CordRepBtree* result = BtreeAdd(tree, append, consumer.Next(3));
+    ASSERT_THAT(result, IsNode(1));
+    ASSERT_THAT(result, Ne(tree));
+    ASSERT_THAT(CordToString(result), Eq(consumer.Consumed()));
+    tree = result;
+    for (size_t i = max_cap + 1; i < max_cap * max_cap; ++i) {
+      refs.RefIf(shared(), tree);
+      result = BtreeAdd(tree, append, consumer.Next(3));
+      ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+      ASSERT_THAT(CordToString(result), Eq(consumer.Consumed()));
+      tree = result;
+    }
+
+    // Fill to maximum at two deep
+    refs.RefIf(shared(), tree);
+    result = BtreeAdd(tree, append, consumer.Next(3));
+    ASSERT_THAT(result, IsNode(2));
+    ASSERT_THAT(result, Ne(tree));
+    ASSERT_THAT(CordToString(result), Eq(consumer.Consumed()));
+    tree = result;
+    for (size_t i = max_cap * max_cap + 1; i < max_cap * max_cap * max_cap;
+         ++i) {
+      refs.RefIf(shared(), tree);
+      result = BtreeAdd(tree, append, consumer.Next(3));
+      ASSERT_THAT(result, Conditional(shared(), Ne(tree), Eq(tree)));
+      ASSERT_THAT(CordToString(result), Eq(consumer.Consumed()));
+      tree = result;
+    }
+
+    CordRep::Unref(tree);
+  }
+}
+
+TEST_P(CordRepBtreeTest, AddLargeDataToLeaf) {
+  const size_t max_cap = CordRepBtree::kMaxCapacity;
+  const size_t n = max_cap * max_cap * max_cap * 3 + 2;
+  const std::string data = CreateRandomString(n * kMaxFlatLength);
+
+  for (bool append : {true, false}) {
+    AutoUnref refs;
+    SCOPED_TRACE(append ? "Append" : "Prepend");
+
+    CordRepBtree* leaf = CordRepBtree::Create(MakeFlat("abc"));
+    refs.RefIf(shared(), leaf);
+    CordRepBtree* result = BtreeAdd(leaf, append, data);
+    EXPECT_THAT(CordToString(result), Eq(append ? "abc" + data : data + "abc"));
+    CordRep::Unref(result);
+  }
+}
+
+TEST_P(CordRepBtreeDualTest, CreateFromConcat) {
+  AutoUnref refs;
+  CordRep* flats[] = {MakeFlat("abcdefgh"), MakeFlat("ijklm"),
+                      MakeFlat("nopqrstuv"), MakeFlat("wxyz")};
+  auto* left = MakeConcat(flats[0], flats[1]);
+  auto* right = MakeConcat(flats[2], refs.RefIf(first_shared(), flats[3]));
+  auto* concat = refs.RefIf(second_shared(), MakeConcat(left, right));
+  CordRepBtree* result = CordRepBtree::Create(concat);
+  ASSERT_TRUE(CordRepBtree::IsValid(result));
+  EXPECT_THAT(result->length, Eq(26));
+  EXPECT_THAT(CordToString(result), Eq("abcdefghijklmnopqrstuvwxyz"));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeDualTest, AppendConcat) {
+  AutoUnref refs;
+  CordRep* flats[] = {MakeFlat("defgh"), MakeFlat("ijklm"),
+                      MakeFlat("nopqrstuv"), MakeFlat("wxyz")};
+  auto* left = MakeConcat(flats[0], flats[1]);
+  auto* right = MakeConcat(flats[2], refs.RefIf(first_shared(), flats[3]));
+  auto* concat = refs.RefIf(second_shared(), MakeConcat(left, right));
+  CordRepBtree* result = CordRepBtree::Create(MakeFlat("abc"));
+  result = CordRepBtree::Append(result, concat);
+  ASSERT_TRUE(CordRepBtree::IsValid(result));
+  EXPECT_THAT(result->length, Eq(26));
+  EXPECT_THAT(CordToString(result), Eq("abcdefghijklmnopqrstuvwxyz"));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeDualTest, PrependConcat) {
+  AutoUnref refs;
+  CordRep* flats[] = {MakeFlat("abcdefgh"), MakeFlat("ijklm"),
+                      MakeFlat("nopqrstuv"), MakeFlat("wx")};
+  auto* left = MakeConcat(flats[0], flats[1]);
+  auto* right = MakeConcat(flats[2], refs.RefIf(first_shared(), flats[3]));
+  auto* concat = refs.RefIf(second_shared(), MakeConcat(left, right));
+  CordRepBtree* result = CordRepBtree::Create(MakeFlat("yz"));
+  result = CordRepBtree::Prepend(result, concat);
+  ASSERT_TRUE(CordRepBtree::IsValid(result));
+  EXPECT_THAT(result->length, Eq(26));
+  EXPECT_THAT(CordToString(result), Eq("abcdefghijklmnopqrstuvwxyz"));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, CreateFromTreeReturnsTree) {
+  AutoUnref refs;
+  CordRepBtree* leaf = CordRepBtree::Create(MakeFlat("Hello world"));
+  refs.RefIf(shared(), leaf);
+  CordRepBtree* result = CordRepBtree::Create(leaf);
+  EXPECT_THAT(result, Eq(leaf));
+  CordRep::Unref(result);
+}
+
+TEST_P(CordRepBtreeTest, ExceedMaxHeight) {
+  AutoUnref refs;
+  CordRepBtree* tree = MakeLeaf();
+  for (int h = 1; h <= CordRepBtree::kMaxHeight; ++h) {
+    CordRepBtree* newtree = CordRepBtree::New(tree);
+    for (size_t i = 1; i < CordRepBtree::kMaxCapacity; ++i) {
+      newtree = CordRepBtree::Append(newtree, CordRep::Ref(tree));
+    }
+    tree = newtree;
+  }
+  refs.RefIf(shared(), tree);
+#if defined(GTEST_HAS_DEATH_TEST)
+  EXPECT_DEATH(tree = CordRepBtree::Append(tree, MakeFlat("Boom")), ".*");
+#endif
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeTest, GetCharacter) {
+  size_t n = CordRepBtree::kMaxCapacity * CordRepBtree::kMaxCapacity + 2;
+  std::string data = CreateRandomString(n * 3);
+  CordRepBtree* tree = CreateTree(data, 3);
+  // Add a substring node for good measure.
+  tree = tree->Append(tree, MakeSubstring(4, 5, MakeFlat("abcdefghijklm")));
+  data += "efghi";
+  for (size_t i = 0; i < data.length(); ++i) {
+    ASSERT_THAT(tree->GetCharacter(i), Eq(data[i]));
+  }
+  CordRep::Unref(tree);
+}
+
+TEST_P(CordRepBtreeTest, IsFlatSingleFlat) {
+  CordRepBtree* leaf = CordRepBtree::Create(MakeFlat("Hello world"));
+
+  absl::string_view fragment;
+  EXPECT_TRUE(leaf->IsFlat(nullptr));
+  EXPECT_TRUE(leaf->IsFlat(&fragment));
+  EXPECT_THAT(fragment, Eq("Hello world"));
+  fragment = "";
+  EXPECT_TRUE(leaf->IsFlat(0, 11, nullptr));
+  EXPECT_TRUE(leaf->IsFlat(0, 11, &fragment));
+  EXPECT_THAT(fragment, Eq("Hello world"));
+
+  // Arbitrary ranges must check true as well.
+  EXPECT_TRUE(leaf->IsFlat(1, 4, &fragment));
+  EXPECT_THAT(fragment, Eq("ello"));
+  EXPECT_TRUE(leaf->IsFlat(6, 5, &fragment));
+  EXPECT_THAT(fragment, Eq("world"));
+
+  CordRep::Unref(leaf);
+}
+
+TEST(CordRepBtreeTest, IsFlatMultiFlat) {
+  size_t n = CordRepBtree::kMaxCapacity * CordRepBtree::kMaxCapacity + 2;
+  std::string data = CreateRandomString(n * 3);
+  CordRepBtree* tree = CreateTree(data, 3);
+  // Add substring nodes for good measure.
+  tree = tree->Append(tree, MakeSubstring(4, 3, MakeFlat("abcdefghijklm")));
+  tree = tree->Append(tree, MakeSubstring(8, 3, MakeFlat("abcdefghijklm")));
+  data += "efgijk";
+
+  EXPECT_FALSE(tree->IsFlat(nullptr));
+  absl::string_view fragment = "Can't touch this";
+  EXPECT_FALSE(tree->IsFlat(&fragment));
+  EXPECT_THAT(fragment, Eq("Can't touch this"));
+
+  for (size_t offset = 0; offset < data.size(); offset += 3) {
+    EXPECT_TRUE(tree->IsFlat(offset, 3, nullptr));
+    EXPECT_TRUE(tree->IsFlat(offset, 3, &fragment));
+    EXPECT_THAT(fragment, Eq(data.substr(offset, 3)));
+
+    fragment = "Can't touch this";
+    if (offset > 0) {
+      EXPECT_FALSE(tree->IsFlat(offset - 1, 4, nullptr));
+      EXPECT_FALSE(tree->IsFlat(offset - 1, 4, &fragment));
+      EXPECT_THAT(fragment, Eq("Can't touch this"));
+    }
+    if (offset < data.size() - 4) {
+      EXPECT_FALSE(tree->IsFlat(offset, 4, nullptr));
+      EXPECT_FALSE(tree->IsFlat(offset, 4, &fragment));
+      EXPECT_THAT(fragment, Eq("Can't touch this"));
+    }
+  }
+
+  CordRep::Unref(tree);
+}
+
+#if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferNotPrivate) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeExternal("Foo"));
+  CordRepBtree::Ref(tree);
+  EXPECT_DEATH(tree->GetAppendBuffer(1), ".*");
+  CordRepBtree::Unref(tree);
+  CordRepBtree::Unref(tree);
+}
+
+#endif  // defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferNotFlat) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeExternal("Foo"));
+  for (int i = 1; i <= height(); ++i) {
+    tree = CordRepBtree::New(tree);
+  }
+  EXPECT_THAT(tree->GetAppendBuffer(1), SizeIs(0));
+  CordRepBtree::Unref(tree);
+}
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferFlatNotPrivate) {
+  CordRepFlat* flat = MakeFlat("abc");
+  CordRepBtree* tree = CordRepBtree::Create(CordRep::Ref(flat));
+  for (int i = 1; i <= height(); ++i) {
+    tree = CordRepBtree::New(tree);
+  }
+  EXPECT_THAT(tree->GetAppendBuffer(1), SizeIs(0));
+  CordRepBtree::Unref(tree);
+  CordRep::Unref(flat);
+}
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferTreeNotPrivate) {
+  if (height() == 0) return;
+  AutoUnref refs;
+  CordRepFlat* flat = MakeFlat("abc");
+  CordRepBtree* tree = CordRepBtree::Create(CordRep::Ref(flat));
+  for (int i = 1; i <= height(); ++i) {
+    if (i == (height() + 1) / 2) refs.Ref(tree);
+    tree = CordRepBtree::New(tree);
+  }
+  EXPECT_THAT(tree->GetAppendBuffer(1), SizeIs(0));
+  CordRepBtree::Unref(tree);
+  CordRep::Unref(flat);
+}
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferFlatNoCapacity) {
+  CordRepFlat* flat = MakeFlat("abc");
+  flat->length = flat->Capacity();
+  CordRepBtree* tree = CordRepBtree::Create(flat);
+  for (int i = 1; i <= height(); ++i) {
+    tree = CordRepBtree::New(tree);
+  }
+  EXPECT_THAT(tree->GetAppendBuffer(1), SizeIs(0));
+  CordRepBtree::Unref(tree);
+}
+
+TEST_P(CordRepBtreeHeightTest, GetAppendBufferFlatWithCapacity) {
+  CordRepFlat* flat = MakeFlat("abc");
+  CordRepBtree* tree = CordRepBtree::Create(flat);
+  for (int i = 1; i <= height(); ++i) {
+    tree = CordRepBtree::New(tree);
+  }
+  absl::Span<char> span = tree->GetAppendBuffer(2);
+  EXPECT_THAT(span, SizeIs(2));
+  EXPECT_THAT(span.data(), TypedEq<void*>(flat->Data() + 3));
+  EXPECT_THAT(tree->length, Eq(5));
+
+  size_t avail = flat->Capacity() - 5;
+  span = tree->GetAppendBuffer(avail + 100);
+  EXPECT_THAT(span, SizeIs(avail));
+  EXPECT_THAT(span.data(), TypedEq<void*>(flat->Data() + 5));
+  EXPECT_THAT(tree->length, Eq(5 + avail));
+
+  CordRepBtree::Unref(tree);
+}
+
+TEST(CordRepBtreeTest, Dump) {
+  // Handles nullptr
+  std::stringstream ss;
+  CordRepBtree::Dump(nullptr, ss);
+  CordRepBtree::Dump(nullptr, "Once upon a label", ss);
+  CordRepBtree::Dump(nullptr, "Once upon a label", false, ss);
+  CordRepBtree::Dump(nullptr, "Once upon a label", true, ss);
+
+  // Cover legal edges
+  CordRepFlat* flat = MakeFlat("Hello world");
+  CordRepExternal* external = MakeExternal("Hello external");
+  CordRep* substr_flat = MakeSubstring(1, 6, CordRep::Ref(flat));
+  CordRep* substr_external = MakeSubstring(2, 7, CordRep::Ref(external));
+
+  // Build tree
+  CordRepBtree* tree = CordRepBtree::Create(flat);
+  tree = CordRepBtree::Append(tree, external);
+  tree = CordRepBtree::Append(tree, substr_flat);
+  tree = CordRepBtree::Append(tree, substr_external);
+
+  // Repeat until we have a tree
+  while (tree->height() == 0) {
+    tree = CordRepBtree::Append(tree, CordRep::Ref(flat));
+    tree = CordRepBtree::Append(tree, CordRep::Ref(external));
+    tree = CordRepBtree::Append(tree, CordRep::Ref(substr_flat));
+    tree = CordRepBtree::Append(tree, CordRep::Ref(substr_external));
+  }
+
+  for (int api = 0; api <= 3; ++api) {
+    absl::string_view api_scope;
+    std::stringstream ss;
+    switch (api) {
+      case 0:
+        api_scope = "Bare";
+        CordRepBtree::Dump(tree, ss);
+        break;
+      case 1:
+        api_scope = "Label only";
+        CordRepBtree::Dump(tree, "Once upon a label", ss);
+        break;
+      case 2:
+        api_scope = "Label no content";
+        CordRepBtree::Dump(tree, "Once upon a label", false, ss);
+        break;
+      default:
+        api_scope = "Label and content";
+        CordRepBtree::Dump(tree, "Once upon a label", true, ss);
+        break;
+    }
+    SCOPED_TRACE(api_scope);
+    std::string str = ss.str();
+
+    // Contains Node(depth) / Leaf and private / shared indicators
+    EXPECT_THAT(str, AllOf(HasSubstr("Node(1)"), HasSubstr("Leaf"),
+                           HasSubstr("Private"), HasSubstr("Shared")));
+
+    // Contains length and start offset of all data edges
+    EXPECT_THAT(str, AllOf(HasSubstr("len = 11"), HasSubstr("len = 14"),
+                           HasSubstr("len = 6"), HasSubstr("len = 7"),
+                           HasSubstr("start = 1"), HasSubstr("start = 2")));
+
+    // Contains address of all data edges
+    EXPECT_THAT(
+        str, AllOf(HasSubstr(absl::StrCat("0x", absl::Hex(flat))),
+                   HasSubstr(absl::StrCat("0x", absl::Hex(external))),
+                   HasSubstr(absl::StrCat("0x", absl::Hex(substr_flat))),
+                   HasSubstr(absl::StrCat("0x", absl::Hex(substr_external)))));
+
+    if (api != 0) {
+      // Contains label
+      EXPECT_THAT(str, HasSubstr("Once upon a label"));
+    }
+
+    if (api != 3) {
+      // Does not contain contents
+      EXPECT_THAT(str, Not(AnyOf((HasSubstr("data = \"Hello world\""),
+                                  HasSubstr("data = \"Hello external\""),
+                                  HasSubstr("data = \"ello w\""),
+                                  HasSubstr("data = \"llo ext\"")))));
+    } else {
+      // Contains contents
+      EXPECT_THAT(str, AllOf((HasSubstr("data = \"Hello world\""),
+                              HasSubstr("data = \"Hello external\""),
+                              HasSubstr("data = \"ello w\""),
+                              HasSubstr("data = \"llo ext\""))));
+    }
+  }
+
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeTest, IsValid) {
+  EXPECT_FALSE(CordRepBtree::IsValid(nullptr));
+
+  CordRepBtree* empty = CordRepBtree::New(0);
+  EXPECT_TRUE(CordRepBtree::IsValid(empty));
+  CordRep::Unref(empty);
+
+  for (bool as_tree : {false, true}) {
+    CordRepBtree* leaf = CordRepBtree::Create(MakeFlat("abc"));
+    CordRepBtree* tree = as_tree ? CordRepBtree::New(leaf) : nullptr;
+    CordRepBtree* check = as_tree ? tree : leaf;
+
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    leaf->length--;
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->length++;
+
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    leaf->tag--;
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->tag++;
+
+    // Height
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    leaf->storage[0] = static_cast<uint8_t>(CordRepBtree::kMaxHeight + 1);
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->storage[0] = 1;
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->storage[0] = 0;
+
+    // Begin
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    const uint8_t begin = leaf->storage[1];
+    leaf->storage[1] = static_cast<uint8_t>(CordRepBtree::kMaxCapacity);
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->storage[1] = 2;
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->storage[1] = begin;
+
+    // End
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    const uint8_t end = leaf->storage[2];
+    leaf->storage[2] = static_cast<uint8_t>(CordRepBtree::kMaxCapacity + 1);
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    leaf->storage[2] = end;
+
+    // DataEdge tag and value
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    CordRep* const edge = leaf->Edges()[0];
+    const uint8_t tag = edge->tag;
+    CordRepBtreeTestPeer::SetEdge(leaf, begin, nullptr);
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    CordRepBtreeTestPeer::SetEdge(leaf, begin, edge);
+    edge->tag = BTREE;
+    EXPECT_FALSE(CordRepBtree::IsValid(check));
+    edge->tag = tag;
+
+    if (as_tree) {
+      ASSERT_TRUE(CordRepBtree::IsValid(check));
+      leaf->length--;
+      EXPECT_FALSE(CordRepBtree::IsValid(check));
+      leaf->length++;
+
+      // Height
+      ASSERT_TRUE(CordRepBtree::IsValid(check));
+      tree->storage[0] = static_cast<uint8_t>(2);
+      EXPECT_FALSE(CordRepBtree::IsValid(check));
+      tree->storage[0] = 1;
+
+      // Btree edge
+      ASSERT_TRUE(CordRepBtree::IsValid(check));
+      CordRep* const edge = tree->Edges()[0];
+      const uint8_t tag = edge->tag;
+      edge->tag = FLAT;
+      EXPECT_FALSE(CordRepBtree::IsValid(check));
+      edge->tag = tag;
+    }
+
+    ASSERT_TRUE(CordRepBtree::IsValid(check));
+    CordRep::Unref(check);
+  }
+}
+
+TEST(CordRepBtreeTest, AssertValid) {
+  CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc"));
+  const CordRepBtree* ctree = tree;
+  EXPECT_THAT(CordRepBtree::AssertValid(tree), Eq(tree));
+  EXPECT_THAT(CordRepBtree::AssertValid(ctree), Eq(ctree));
+
+#if defined(GTEST_HAS_DEATH_TEST)
+  CordRepBtree* nulltree = nullptr;
+  const CordRepBtree* cnulltree = nullptr;
+  EXPECT_DEBUG_DEATH(
+      EXPECT_THAT(CordRepBtree::AssertValid(nulltree), Eq(nulltree)), ".*");
+  EXPECT_DEBUG_DEATH(
+      EXPECT_THAT(CordRepBtree::AssertValid(cnulltree), Eq(cnulltree)), ".*");
+
+  tree->length--;
+  EXPECT_DEBUG_DEATH(EXPECT_THAT(CordRepBtree::AssertValid(tree), Eq(tree)),
+                     ".*");
+  EXPECT_DEBUG_DEATH(EXPECT_THAT(CordRepBtree::AssertValid(ctree), Eq(ctree)),
+                     ".*");
+  tree->length++;
+#endif
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepBtreeTest, CheckAssertValidShallowVsDeep) {
+  // Restore exhaustive validation on any exit.
+  const bool exhaustive_validation = cord_btree_exhaustive_validation.load();
+  auto cleanup = absl::MakeCleanup([exhaustive_validation] {
+    cord_btree_exhaustive_validation.store(exhaustive_validation);
+  });
+
+  // Create a tree of at least 2 levels, and mess with the original flat, which
+  // should go undetected in shallow mode as the flat is too far away, but
+  // should be detected in forced non-shallow mode.
+  CordRep* flat = MakeFlat("abc");
+  CordRepBtree* tree = CordRepBtree::Create(flat);
+  constexpr size_t max_cap = CordRepBtree::kMaxCapacity;
+  const size_t n = max_cap * max_cap * 2;
+  for (size_t i = 0; i < n; ++i) {
+    tree = CordRepBtree::Append(tree, MakeFlat("Hello world"));
+  }
+  flat->length = 100;
+
+  cord_btree_exhaustive_validation.store(false);
+  EXPECT_FALSE(CordRepBtree::IsValid(tree));
+  EXPECT_TRUE(CordRepBtree::IsValid(tree, true));
+  EXPECT_FALSE(CordRepBtree::IsValid(tree, false));
+  CordRepBtree::AssertValid(tree);
+  CordRepBtree::AssertValid(tree, true);
+#if defined(GTEST_HAS_DEATH_TEST)
+  EXPECT_DEBUG_DEATH(CordRepBtree::AssertValid(tree, false), ".*");
+#endif
+
+  cord_btree_exhaustive_validation.store(true);
+  EXPECT_FALSE(CordRepBtree::IsValid(tree));
+  EXPECT_FALSE(CordRepBtree::IsValid(tree, true));
+  EXPECT_FALSE(CordRepBtree::IsValid(tree, false));
+#if defined(GTEST_HAS_DEATH_TEST)
+  EXPECT_DEBUG_DEATH(CordRepBtree::AssertValid(tree), ".*");
+  EXPECT_DEBUG_DEATH(CordRepBtree::AssertValid(tree, true), ".*");
+#endif
+
+  flat->length = 3;
+  CordRep::Unref(tree);
+}
+
+}  // namespace
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.cc
new file mode 100644
index 00000000000..81514543db6
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.cc
@@ -0,0 +1,129 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_consume.h"
+
+#include <array>
+#include <utility>
+
+#include "absl/container/inlined_vector.h"
+#include "absl/functional/function_ref.h"
+#include "absl/strings/internal/cord_internal.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+namespace {
+
+// Unrefs the provided `substring`, and returns `substring->child`
+// Adds or assumes a reference on `substring->child`
+CordRep* ClipSubstring(CordRepSubstring* substring) {
+  CordRep* child = substring->child;
+  if (substring->refcount.IsOne()) {
+    delete substring;
+  } else {
+    CordRep::Ref(child);
+    CordRep::Unref(substring);
+  }
+  return child;
+}
+
+// Unrefs the provided `concat`, and returns `{concat->left, concat->right}`
+// Adds or assumes a reference on `concat->left` and `concat->right`.
+// Returns an array of 2 elements containing the left and right nodes.
+std::array<CordRep*, 2> ClipConcat(CordRepConcat* concat) {
+  std::array<CordRep*, 2> result{concat->left, concat->right};
+  if (concat->refcount.IsOne()) {
+    delete concat;
+  } else {
+    CordRep::Ref(result[0]);
+    CordRep::Ref(result[1]);
+    CordRep::Unref(concat);
+  }
+  return result;
+}
+
+void Consume(bool forward, CordRep* rep, ConsumeFn consume_fn) {
+  size_t offset = 0;
+  size_t length = rep->length;
+  struct Entry {
+    CordRep* rep;
+    size_t offset;
+    size_t length;
+  };
+  absl::InlinedVector<Entry, 40> stack;
+
+  for (;;) {
+    if (rep->tag == CONCAT) {
+      std::array<CordRep*, 2> res = ClipConcat(rep->concat());
+      CordRep* left = res[0];
+      CordRep* right = res[1];
+
+      if (left->length <= offset) {
+        // Don't need left node
+        offset -= left->length;
+        CordRep::Unref(left);
+        rep = right;
+        continue;
+      }
+
+      size_t length_left = left->length - offset;
+      if (length_left >= length) {
+        // Don't need right node
+        CordRep::Unref(right);
+        rep = left;
+        continue;
+      }
+
+      // Need both nodes
+      size_t length_right = length - length_left;
+      if (forward) {
+        stack.push_back({right, 0, length_right});
+        rep = left;
+        length = length_left;
+      } else {
+        stack.push_back({left, offset, length_left});
+        rep = right;
+        offset = 0;
+        length = length_right;
+      }
+    } else if (rep->tag == SUBSTRING) {
+      offset += rep->substring()->start;
+      rep = ClipSubstring(rep->substring());
+    } else {
+      consume_fn(rep, offset, length);
+      if (stack.empty()) return;
+
+      rep = stack.back().rep;
+      offset = stack.back().offset;
+      length = stack.back().length;
+      stack.pop_back();
+    }
+  }
+}
+
+}  // namespace
+
+void Consume(CordRep* rep, ConsumeFn consume_fn) {
+  return Consume(true, rep, std::move(consume_fn));
+}
+
+void ReverseConsume(CordRep* rep, ConsumeFn consume_fn) {
+  return Consume(false, rep, std::move(consume_fn));
+}
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.h
new file mode 100644
index 00000000000..d46fca2b217
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume.h
@@ -0,0 +1,50 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_CONSUME_H_
+#define ABSL_STRINGS_INTERNAL_CORD_REP_CONSUME_H_
+
+#include <functional>
+
+#include "absl/functional/function_ref.h"
+#include "absl/strings/internal/cord_internal.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+// Functor for the Consume() and ReverseConsume() functions:
+//   void ConsumeFunc(CordRep* rep, size_t offset, size_t length);
+// See the Consume() and ReverseConsume() function comments for documentation.
+using ConsumeFn = FunctionRef<void(CordRep*, size_t, size_t)>;
+
+// Consume() and ReverseConsume() consume CONCAT based trees and invoke the
+// provided functor with the contained nodes in the proper forward or reverse
+// order, which is used to convert CONCAT trees into other tree or cord data.
+// All CONCAT and SUBSTRING nodes are processed internally. The 'offset`
+// parameter of the functor is non-zero for any nodes below SUBSTRING nodes.
+// It's up to the caller to form these back into SUBSTRING nodes or otherwise
+// store offset / prefix information. These functions are intended to be used
+// only for migration / transitional code where due to factors such as ODR
+// violations, we can not 100% guarantee that all code respects 'new format'
+// settings and flags, so we need to be able to parse old data on the fly until
+// all old code is deprecated / no longer the default format.
+void Consume(CordRep* rep, ConsumeFn consume_fn);
+void ReverseConsume(CordRep* rep, ConsumeFn consume_fn);
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_CONSUME_H_
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume_test.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume_test.cc
new file mode 100644
index 00000000000..e507824b4f8
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_consume_test.cc
@@ -0,0 +1,173 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/cord_rep_consume.h"
+
+#include <functional>
+#include <utility>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+namespace {
+
+using testing::InSequence;
+using testing::MockFunction;
+
+// Returns the depth of a node
+int Depth(const CordRep* rep) {
+  return (rep->tag == CONCAT) ? rep->concat()->depth() : 0;
+}
+
+// Creates a concatenation of the specified nodes.
+CordRepConcat* CreateConcat(CordRep* left, CordRep* right) {
+  auto* concat = new CordRepConcat();
+  concat->tag = CONCAT;
+  concat->left = left;
+  concat->right = right;
+  concat->length = left->length + right->length;
+  concat->set_depth(1 + (std::max)(Depth(left), Depth(right)));
+  return concat;
+}
+
+// Creates a flat with the length set to `length`
+CordRepFlat* CreateFlatWithLength(size_t length) {
+  auto* flat = CordRepFlat::New(length);
+  flat->length = length;
+  return flat;
+}
+
+// Creates a substring node on the specified child.
+CordRepSubstring* CreateSubstring(CordRep* child, size_t start, size_t length) {
+  auto* rep = new CordRepSubstring();
+  rep->length = length;
+  rep->tag = SUBSTRING;
+  rep->start = start;
+  rep->child = child;
+  return rep;
+}
+
+// Flats we use in the tests
+CordRep* flat[6];
+
+// Creates a test tree
+CordRep* CreateTestTree() {
+  flat[0] = CreateFlatWithLength(1);
+  flat[1] = CreateFlatWithLength(7);
+  CordRepConcat* left = CreateConcat(flat[0], CreateSubstring(flat[1], 2, 4));
+
+  flat[2] = CreateFlatWithLength(9);
+  flat[3] = CreateFlatWithLength(13);
+  CordRepConcat* right1 = CreateConcat(flat[2], flat[3]);
+
+  flat[4] = CreateFlatWithLength(15);
+  flat[5] = CreateFlatWithLength(19);
+  CordRepConcat* right2 = CreateConcat(flat[4], flat[5]);
+
+  CordRepConcat* right = CreateConcat(right1, CreateSubstring(right2, 5, 17));
+  return CreateConcat(left, right);
+}
+
+TEST(CordRepConsumeTest, Consume) {
+  InSequence in_sequence;
+  CordRep* tree = CreateTestTree();
+  MockFunction<void(CordRep*, size_t, size_t)> consume;
+  EXPECT_CALL(consume, Call(flat[0], 0, 1));
+  EXPECT_CALL(consume, Call(flat[1], 2, 4));
+  EXPECT_CALL(consume, Call(flat[2], 0, 9));
+  EXPECT_CALL(consume, Call(flat[3], 0, 13));
+  EXPECT_CALL(consume, Call(flat[4], 5, 10));
+  EXPECT_CALL(consume, Call(flat[5], 0, 7));
+  Consume(tree, consume.AsStdFunction());
+  for (CordRep* rep : flat) {
+    EXPECT_TRUE(rep->refcount.IsOne());
+    CordRep::Unref(rep);
+  }
+}
+
+TEST(CordRepConsumeTest, ConsumeShared) {
+  InSequence in_sequence;
+  CordRep* tree = CreateTestTree();
+  MockFunction<void(CordRep*, size_t, size_t)> consume;
+  EXPECT_CALL(consume, Call(flat[0], 0, 1));
+  EXPECT_CALL(consume, Call(flat[1], 2, 4));
+  EXPECT_CALL(consume, Call(flat[2], 0, 9));
+  EXPECT_CALL(consume, Call(flat[3], 0, 13));
+  EXPECT_CALL(consume, Call(flat[4], 5, 10));
+  EXPECT_CALL(consume, Call(flat[5], 0, 7));
+  Consume(CordRep::Ref(tree), consume.AsStdFunction());
+  for (CordRep* rep : flat) {
+    EXPECT_FALSE(rep->refcount.IsOne());
+    CordRep::Unref(rep);
+  }
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepConsumeTest, Reverse) {
+  InSequence in_sequence;
+  CordRep* tree = CreateTestTree();
+  MockFunction<void(CordRep*, size_t, size_t)> consume;
+  EXPECT_CALL(consume, Call(flat[5], 0, 7));
+  EXPECT_CALL(consume, Call(flat[4], 5, 10));
+  EXPECT_CALL(consume, Call(flat[3], 0, 13));
+  EXPECT_CALL(consume, Call(flat[2], 0, 9));
+  EXPECT_CALL(consume, Call(flat[1], 2, 4));
+  EXPECT_CALL(consume, Call(flat[0], 0, 1));
+  ReverseConsume(tree, consume.AsStdFunction());
+  for (CordRep* rep : flat) {
+    EXPECT_TRUE(rep->refcount.IsOne());
+    CordRep::Unref(rep);
+  }
+}
+
+TEST(CordRepConsumeTest, ReverseShared) {
+  InSequence in_sequence;
+  CordRep* tree = CreateTestTree();
+  MockFunction<void(CordRep*, size_t, size_t)> consume;
+  EXPECT_CALL(consume, Call(flat[5], 0, 7));
+  EXPECT_CALL(consume, Call(flat[4], 5, 10));
+  EXPECT_CALL(consume, Call(flat[3], 0, 13));
+  EXPECT_CALL(consume, Call(flat[2], 0, 9));
+  EXPECT_CALL(consume, Call(flat[1], 2, 4));
+  EXPECT_CALL(consume, Call(flat[0], 0, 1));
+  ReverseConsume(CordRep::Ref(tree), consume.AsStdFunction());
+  for (CordRep* rep : flat) {
+    EXPECT_FALSE(rep->refcount.IsOne());
+    CordRep::Unref(rep);
+  }
+  CordRep::Unref(tree);
+}
+
+TEST(CordRepConsumeTest, UnreachableFlat) {
+  InSequence in_sequence;
+  CordRepFlat* flat1 = CreateFlatWithLength(10);
+  CordRepFlat* flat2 = CreateFlatWithLength(20);
+  CordRepConcat* concat = CreateConcat(flat1, flat2);
+  CordRepSubstring* tree = CreateSubstring(concat, 15, 10);
+  MockFunction<void(CordRep*, size_t, size_t)> consume;
+  EXPECT_CALL(consume, Call(flat2, 5, 10));
+  Consume(tree, consume.AsStdFunction());
+  EXPECT_TRUE(flat2->refcount.IsOne());
+  CordRep::Unref(flat2);
+}
+
+}  // namespace
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_flat.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_flat.h
index a98aa9df5fe..4d0f988697f 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_flat.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_flat.h
@@ -44,11 +44,11 @@ static constexpr size_t kMaxFlatLength = kMaxFlatSize - kFlatOverhead;
 static constexpr size_t kMinFlatLength = kMinFlatSize - kFlatOverhead;
 
 constexpr uint8_t AllocatedSizeToTagUnchecked(size_t size) {
-  return static_cast<uint8_t>((size <= 1024) ? size / 8
-                                             : 128 + size / 32 - 1024 / 32);
+  return static_cast<uint8_t>((size <= 1024) ? size / 8 + 1
+                                             : 129 + size / 32 - 1024 / 32);
 }
 
-static_assert(kMinFlatSize / 8 >= FLAT, "");
+static_assert(kMinFlatSize / 8 + 1 >= FLAT, "");
 static_assert(AllocatedSizeToTagUnchecked(kMaxFlatSize) <= MAX_FLAT_TAG, "");
 
 // Helper functions for rounded div, and rounding to exact sizes.
@@ -73,7 +73,7 @@ inline uint8_t AllocatedSizeToTag(size_t size) {
 
 // Converts the provided tag to the corresponding allocated size
 constexpr size_t TagToAllocatedSize(uint8_t tag) {
-  return (tag <= 128) ? (tag * 8) : (1024 + (tag - 128) * 32);
+  return (tag <= 129) ? ((tag - 1) * 8) : (1024 + (tag - 129) * 32);
 }
 
 // Converts the provided tag to the corresponding available data length
@@ -82,7 +82,7 @@ constexpr size_t TagToLength(uint8_t tag) {
 }
 
 // Enforce that kMaxFlatSize maps to a well-known exact tag value.
-static_assert(TagToAllocatedSize(224) == kMaxFlatSize, "Bad tag logic");
+static_assert(TagToAllocatedSize(225) == kMaxFlatSize, "Bad tag logic");
 
 struct CordRepFlat : public CordRep {
   // Creates a new flat node.
@@ -118,8 +118,8 @@ struct CordRepFlat : public CordRep {
   }
 
   // Returns a pointer to the data inside this flat rep.
-  char* Data() { return storage; }
-  const char* Data() const { return storage; }
+  char* Data() { return reinterpret_cast<char*>(storage); }
+  const char* Data() const { return reinterpret_cast<const char*>(storage); }
 
   // Returns the maximum capacity (payload size) of this instance.
   size_t Capacity() const { return TagToLength(tag); }
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.cc
index f78c94e19bb..db1f63fa671 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.cc
@@ -26,6 +26,7 @@
 #include "absl/base/macros.h"
 #include "absl/container/inlined_vector.h"
 #include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_consume.h"
 #include "absl/strings/internal/cord_rep_flat.h"
 
 namespace absl {
@@ -39,7 +40,7 @@ using index_type = CordRepRing::index_type;
 enum class Direction { kForward, kReversed };
 
 inline bool IsFlatOrExternal(CordRep* rep) {
-  return rep->tag >= FLAT || rep->tag == EXTERNAL;
+  return rep->IsFlat() || rep->IsExternal();
 }
 
 // Verifies that n + extra <= kMaxCapacity: throws std::length_error otherwise.
@@ -49,14 +50,6 @@ inline void CheckCapacity(size_t n, size_t extra) {
   }
 }
 
-// Removes a reference from `rep` only.
-// Asserts that the refcount after decrement is not zero.
-inline bool UnrefNeverOne(CordRep* rep) {
-  bool result = rep->refcount.Decrement();
-  assert(result);
-  return result;
-}
-
 // Creates a flat from the provided string data, allocating up to `extra`
 // capacity in the returned flat depending on kMaxFlatLength limitations.
 // Requires `len` to be less or equal to `kMaxFlatLength`
@@ -68,40 +61,6 @@ CordRepFlat* CreateFlat(const char* s, size_t n, size_t extra = 0) {  // NOLINT
   return rep;
 }
 
-// Unrefs the provided `substring`, and returns `substring->child`
-// Adds or assumes a reference on `substring->child`
-CordRep* ClipSubstring(CordRepSubstring* substring) {
-  CordRep* child = substring->child;
-  if (substring->refcount.IsOne()) {
-    delete substring;
-  } else {
-    CordRep::Ref(child);
-    if (ABSL_PREDICT_FALSE(!substring->refcount.Decrement())) {
-      UnrefNeverOne(child);
-      delete substring;
-    }
-  }
-  return child;
-}
-
-// Unrefs the provided `concat`, and returns `{concat->left, concat->right}`
-// Adds or assumes a reference on `concat->left` and `concat->right`.
-std::pair<CordRep*, CordRep*> ClipConcat(CordRepConcat* concat) {
-  auto result = std::make_pair(concat->left, concat->right);
-  if (concat->refcount.IsOne()) {
-    delete concat;
-  } else {
-    CordRep::Ref(result.first);
-    CordRep::Ref(result.second);
-    if (ABSL_PREDICT_FALSE(!concat->refcount.Decrement())) {
-      UnrefNeverOne(result.first);
-      UnrefNeverOne(result.second);
-      delete concat;
-    }
-  }
-  return result;
-}
-
 // Unrefs the entries in `[head, tail)`.
 // Requires all entries to be a FLAT or EXTERNAL node.
 void UnrefEntries(const CordRepRing* rep, index_type head, index_type tail) {
@@ -117,79 +76,6 @@ void UnrefEntries(const CordRepRing* rep, index_type head, index_type tail) {
   });
 }
 
-template <typename F>
-void Consume(Direction direction, CordRep* rep, F&& fn) {
-  size_t offset = 0;
-  size_t length = rep->length;
-  struct Entry {
-    CordRep* rep;
-    size_t offset;
-    size_t length;
-  };
-  absl::InlinedVector<Entry, 40> stack;
-
-  for (;;) {
-    if (rep->tag >= FLAT || rep->tag == EXTERNAL || rep->tag == RING) {
-      fn(rep, offset, length);
-      if (stack.empty()) return;
-
-      rep = stack.back().rep;
-      offset = stack.back().offset;
-      length = stack.back().length;
-      stack.pop_back();
-    } else if (rep->tag == SUBSTRING) {
-      offset += rep->substring()->start;
-      rep = ClipSubstring(rep->substring());
-    } else if (rep->tag == CONCAT) {
-      auto res = ClipConcat(rep->concat());
-      CordRep* left = res.first;
-      CordRep* right = res.second;
-
-      if (left->length <= offset) {
-        // Don't need left node
-        offset -= left->length;
-        CordRep::Unref(left);
-        rep = right;
-        continue;
-      }
-
-      size_t length_left = left->length - offset;
-      if (length_left >= length) {
-        // Don't need right node
-        CordRep::Unref(right);
-        rep = left;
-        continue;
-      }
-
-      // Need both nodes
-      size_t length_right = length - length_left;
-      if (direction == Direction::kReversed) {
-        stack.push_back({left, offset, length_left});
-        rep = right;
-        offset = 0;
-        length = length_right;
-      } else {
-        stack.push_back({right, 0, length_right});
-        rep = left;
-        length = length_left;
-      }
-    } else {
-      assert("Valid tag" == nullptr);
-      return;
-    }
-  }
-}
-
-template <typename F>
-void Consume(CordRep* rep, F&& fn) {
-  return Consume(Direction::kForward, rep, std::forward<F>(fn));
-}
-
-template <typename F>
-void RConsume(CordRep* rep, F&& fn) {
-  return Consume(Direction::kReversed, rep, std::forward<F>(fn));
-}
-
 }  // namespace
 
 std::ostream& operator<<(std::ostream& s, const CordRepRing& rep) {
@@ -343,7 +229,7 @@ void CordRepRing::SetCapacityForTesting(size_t capacity) {
 }
 
 void CordRepRing::Delete(CordRepRing* rep) {
-  assert(rep != nullptr && rep->tag == RING);
+  assert(rep != nullptr && rep->IsRing());
 #if defined(__cpp_sized_deallocation)
   size_t size = AllocSize(rep->capacity_);
   rep->~CordRepRing();
@@ -474,7 +360,7 @@ CordRepRing* CordRepRing::Create(CordRep* child, size_t extra) {
   if (IsFlatOrExternal(child)) {
     return CreateFromLeaf(child, 0, length, extra);
   }
-  if (child->tag == RING) {
+  if (child->IsRing()) {
     return Mutable(child->ring(), extra);
   }
   return CreateSlow(child, extra);
@@ -547,7 +433,7 @@ CordRepRing* CordRepRing::AddRing(CordRepRing* rep, CordRepRing* ring,
 
 CordRepRing* CordRepRing::AppendSlow(CordRepRing* rep, CordRep* child) {
   Consume(child, [&rep](CordRep* child_arg, size_t offset, size_t len) {
-    if (child_arg->tag == RING) {
+    if (child_arg->IsRing()) {
       rep = AddRing<AddMode::kAppend>(rep, child_arg->ring(), offset, len);
     } else {
       rep = AppendLeaf(rep, child_arg, offset, len);
@@ -574,14 +460,14 @@ CordRepRing* CordRepRing::Append(CordRepRing* rep, CordRep* child) {
   if (IsFlatOrExternal(child)) {
     return AppendLeaf(rep, child, 0, length);
   }
-  if (child->tag == RING) {
+  if (child->IsRing()) {
     return AddRing<AddMode::kAppend>(rep, child->ring(), 0, length);
   }
   return AppendSlow(rep, child);
 }
 
 CordRepRing* CordRepRing::PrependSlow(CordRepRing* rep, CordRep* child) {
-  RConsume(child, [&](CordRep* child_arg, size_t offset, size_t len) {
+  ReverseConsume(child, [&](CordRep* child_arg, size_t offset, size_t len) {
     if (IsFlatOrExternal(child_arg)) {
       rep = PrependLeaf(rep, child_arg, offset, len);
     } else {
@@ -610,7 +496,7 @@ CordRepRing* CordRepRing::Prepend(CordRepRing* rep, CordRep* child) {
   if (IsFlatOrExternal(child)) {
     return PrependLeaf(rep, child, 0, length);
   }
-  if (child->tag == RING) {
+  if (child->IsRing()) {
     return AddRing<AddMode::kPrepend>(rep, child->ring(), 0, length);
   }
   return PrependSlow(rep, child);
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.h
index 2082a5653f4..44db849430a 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_ring.h
@@ -570,12 +570,12 @@ inline CordRepRing::Position CordRepRing::FindTail(index_type head,
 
 // Now that CordRepRing is defined, we can define CordRep's helper casts:
 inline CordRepRing* CordRep::ring() {
-  assert(tag == RING);
+  assert(IsRing());
   return static_cast<CordRepRing*>(this);
 }
 
 inline const CordRepRing* CordRep::ring() const {
-  assert(tag == RING);
+  assert(IsRing());
   return static_cast<const CordRepRing*>(this);
 }
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_test_util.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_test_util.h
new file mode 100644
index 00000000000..bc500064c93
--- /dev/null
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_test_util.h
@@ -0,0 +1,185 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_TEST_UTIL_H_
+#define ABSL_STRINGS_INTERNAL_CORD_REP_TEST_UTIL_H_
+
+#include <cassert>
+#include <memory>
+#include <random>
+#include <string>
+#include <vector>
+
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
+#include "absl/strings/internal/cord_rep_flat.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cordrep_testing {
+
+inline cord_internal::CordRepSubstring* MakeSubstring(
+    size_t start, size_t len, cord_internal::CordRep* rep) {
+  auto* sub = new cord_internal::CordRepSubstring;
+  sub->tag = cord_internal::SUBSTRING;
+  sub->start = start;
+  sub->length = len <= 0 ? rep->length - start + len : len;
+  sub->child = rep;
+  return sub;
+}
+
+inline cord_internal::CordRepConcat* MakeConcat(cord_internal::CordRep* left,
+                                                cord_internal::CordRep* right,
+                                                int depth = 0) {
+  auto* concat = new cord_internal::CordRepConcat;
+  concat->tag = cord_internal::CONCAT;
+  concat->length = left->length + right->length;
+  concat->left = left;
+  concat->right = right;
+  concat->set_depth(depth);
+  return concat;
+}
+
+inline cord_internal::CordRepFlat* MakeFlat(absl::string_view value) {
+  assert(value.length() <= cord_internal::kMaxFlatLength);
+  auto* flat = cord_internal::CordRepFlat::New(value.length());
+  flat->length = value.length();
+  memcpy(flat->Data(), value.data(), value.length());
+  return flat;
+}
+
+// Creates an external node for testing
+inline cord_internal::CordRepExternal* MakeExternal(absl::string_view s) {
+  struct Rep : public cord_internal::CordRepExternal {
+    std::string s;
+    explicit Rep(absl::string_view sv) : s(sv) {
+      this->tag = cord_internal::EXTERNAL;
+      this->base = s.data();
+      this->length = s.length();
+      this->releaser_invoker = [](cord_internal::CordRepExternal* self) {
+        delete static_cast<Rep*>(self);
+      };
+    }
+  };
+  return new Rep(s);
+}
+
+inline std::string CreateRandomString(size_t n) {
+  absl::string_view data =
+      "abcdefghijklmnopqrstuvwxyz"
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+      "0123456789~!@#$%^&*()_+=-<>?:\"{}[]|";
+  std::minstd_rand rnd;
+  std::uniform_int_distribution<size_t> dist(0, data.size() - 1);
+  std::string s(n, ' ');
+  for (size_t i = 0; i < n; ++i) {
+    s[i] = data[dist(rnd)];
+  }
+  return s;
+}
+
+// Creates an array of flats from the provided string, chopping
+// the provided string up into flats of size `chunk_size` characters
+// resulting in roughly `data.size() / chunk_size` total flats.
+inline std::vector<cord_internal::CordRep*> CreateFlatsFromString(
+    absl::string_view data, size_t chunk_size) {
+  assert(chunk_size > 0);
+  std::vector<cord_internal::CordRep*> flats;
+  for (absl::string_view s = data; !s.empty(); s.remove_prefix(chunk_size)) {
+    flats.push_back(MakeFlat(s.substr(0, chunk_size)));
+  }
+  return flats;
+}
+
+inline cord_internal::CordRepBtree* CordRepBtreeFromFlats(
+    absl::Span<cord_internal::CordRep* const> flats) {
+  assert(!flats.empty());
+  auto* node = cord_internal::CordRepBtree::Create(flats[0]);
+  for (size_t i = 1; i < flats.size(); ++i) {
+    node = cord_internal::CordRepBtree::Append(node, flats[i]);
+  }
+  return node;
+}
+
+inline void CordToString(cord_internal::CordRep* rep, std::string& s) {
+  size_t offset = 0;
+  size_t length = rep->length;
+  while (rep->tag == cord_internal::SUBSTRING) {
+    offset += rep->substring()->start;
+    rep = rep->substring()->child;
+  }
+  if (rep->tag == cord_internal::BTREE) {
+    for (cord_internal::CordRep* edge : rep->btree()->Edges()) {
+      CordToString(edge, s);
+    }
+  } else if (rep->tag >= cord_internal::FLAT) {
+    s.append(rep->flat()->Data() + offset, length);
+  } else if (rep->tag == cord_internal::EXTERNAL) {
+    s.append(rep->external()->base + offset, length);
+  } else {
+    ABSL_RAW_LOG(FATAL, "Unsupported tag %d", rep->tag);
+  }
+}
+
+inline std::string CordToString(cord_internal::CordRep* rep) {
+  std::string s;
+  s.reserve(rep->length);
+  CordToString(rep, s);
+  return s;
+}
+
+// RAII Helper class to automatically unref reps on destruction.
+class AutoUnref {
+ public:
+  ~AutoUnref() {
+    for (CordRep* rep : unrefs_) CordRep::Unref(rep);
+  }
+
+  // Adds `rep` to the list of reps to be unreffed at destruction.
+  template <typename CordRepType>
+  CordRepType* Add(CordRepType* rep) {
+    unrefs_.push_back(rep);
+    return rep;
+  }
+
+  // Increments the reference count of `rep` by one, and adds it to
+  // the list of reps to be unreffed at destruction.
+  template <typename CordRepType>
+  CordRepType* Ref(CordRepType* rep) {
+    unrefs_.push_back(CordRep::Ref(rep));
+    return rep;
+  }
+
+  // Increments the reference count of `rep` by one if `condition` is true,
+  // and adds it to the list of reps to be unreffed at destruction.
+  template <typename CordRepType>
+  CordRepType* RefIf(bool condition, CordRepType* rep) {
+    if (condition) unrefs_.push_back(CordRep::Ref(rep));
+    return rep;
+  }
+
+ private:
+  using CordRep = absl::cord_internal::CordRep;
+
+  std::vector<CordRep*> unrefs_;
+};
+
+}  // namespace cordrep_testing
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_TEST_UTIL_H_
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_functions.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_functions.cc
index f30080f8c24..48369933c9b 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_functions.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_functions.cc
@@ -24,13 +24,6 @@
 #include "absl/base/internal/exponential_biased.h"
 #include "absl/base/internal/raw_logging.h"
 
-// TODO(b/162942788): weak 'cordz_disabled' value.
-// A strong version is in the 'cordz_disabled_hack_for_odr' library which can
-// be linked in to disable cordz at compile time.
-extern "C" {
-bool absl_internal_cordz_disabled ABSL_ATTRIBUTE_WEAK = false;
-}
-
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace cord_internal {
@@ -54,13 +47,6 @@ ABSL_CONST_INIT thread_local int64_t cordz_next_sample = kInitCordzNextSample;
 constexpr int64_t kIntervalIfDisabled = 1 << 16;
 
 ABSL_ATTRIBUTE_NOINLINE bool cordz_should_profile_slow() {
-  // TODO(b/162942788): check if profiling is disabled at compile time.
-  if (absl_internal_cordz_disabled) {
-    ABSL_RAW_LOG(WARNING, "Cordz info disabled at compile time");
-    // We are permanently disabled: set counter to highest possible value.
-    cordz_next_sample = std::numeric_limits<int64_t>::max();
-    return false;
-  }
 
   thread_local absl::base_internal::ExponentialBiased
       exponential_biased_generator;
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info.cc
index a3a0b9c046d..5c18bbc566d 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info.cc
@@ -19,6 +19,7 @@
 #include "absl/container/inlined_vector.h"
 #include "absl/debugging/stacktrace.h"
 #include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_ring.h"
 #include "absl/strings/internal/cordz_handle.h"
 #include "absl/strings/internal/cordz_statistics.h"
@@ -83,19 +84,23 @@ class CordRepAnalyzer {
     // Process all top level linear nodes (substrings and flats).
     repref = CountLinearReps(repref, memory_usage_);
 
-    // We should have have either a concat or ring node node if not null.
     if (repref.rep != nullptr) {
-      assert(repref.rep->tag == RING || repref.rep->tag == CONCAT);
       if (repref.rep->tag == RING) {
         AnalyzeRing(repref);
+      } else if (repref.rep->tag == BTREE) {
+        AnalyzeBtree(repref);
       } else if (repref.rep->tag == CONCAT) {
         AnalyzeConcat(repref);
+      } else {
+        // We should have either a concat, btree, or ring node if not null.
+        assert(false);
       }
     }
 
     // Adds values to output
     statistics_.estimated_memory_usage += memory_usage_.total;
-    statistics_.estimated_fair_share_memory_usage += memory_usage_.fair_share;
+    statistics_.estimated_fair_share_memory_usage +=
+        static_cast<size_t>(memory_usage_.fair_share);
   }
 
  private:
@@ -117,13 +122,13 @@ class CordRepAnalyzer {
   // Memory usage values
   struct MemoryUsage {
     size_t total = 0;
-    size_t fair_share = 0;
+    double fair_share = 0.0;
 
     // Adds 'size` memory usage to this class, with a cumulative (recursive)
     // reference count of `refcount`
     void Add(size_t size, size_t refcount) {
       total += size;
-      fair_share += size / refcount;
+      fair_share += static_cast<double>(size) / refcount;
     }
   };
 
@@ -215,28 +220,32 @@ class CordRepAnalyzer {
     }
   }
 
-  // Counts the provided ring buffer child into `child_usage`.
-  void CountRingChild(const CordRep* child, MemoryUsage& child_usage) {
-    RepRef rep{child, static_cast<size_t>(child->refcount.Get())};
-    rep = CountLinearReps(rep, child_usage);
-    assert(rep.rep == nullptr);
-  }
-
-  // Analyzes the provided ring. As ring buffers can have many child nodes, the
-  // effect of rounding errors can become non trivial, so we compute the totals
-  // first at the ring level, and then divide the fair share of the total
-  // including children fair share totals.
+  // Analyzes the provided ring.
   void AnalyzeRing(RepRef rep) {
     statistics_.node_count++;
     statistics_.node_counts.ring++;
-    MemoryUsage ring_usage;
     const CordRepRing* ring = rep.rep->ring();
-    ring_usage.Add(CordRepRing::AllocSize(ring->capacity()), 1);
+    memory_usage_.Add(CordRepRing::AllocSize(ring->capacity()), rep.refcount);
     ring->ForEach([&](CordRepRing::index_type pos) {
-      CountRingChild(ring->entry_child(pos), ring_usage);
+      CountLinearReps(rep.Child(ring->entry_child(pos)), memory_usage_);
     });
-    memory_usage_.total += ring_usage.total;
-    memory_usage_.fair_share += ring_usage.fair_share / rep.refcount;
+  }
+
+  // Analyzes the provided btree.
+  void AnalyzeBtree(RepRef rep) {
+    statistics_.node_count++;
+    statistics_.node_counts.btree++;
+    memory_usage_.Add(sizeof(CordRepBtree), rep.refcount);
+    const CordRepBtree* tree = rep.rep->btree();
+    if (tree->height() > 0) {
+      for (CordRep* edge : tree->Edges()) {
+        AnalyzeBtree(rep.Child(edge));
+      }
+    } else {
+      for (CordRep* edge : tree->Edges()) {
+        CountLinearReps(rep.Child(edge), memory_usage_);
+      }
+    }
   }
 
   CordzStatistics& statistics_;
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info_statistics_test.cc b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info_statistics_test.cc
index 9f2842d97d4..7430d281cae 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info_statistics_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_info_statistics_test.cc
@@ -21,6 +21,7 @@
 #include "absl/base/config.h"
 #include "absl/strings/cord.h"
 #include "absl/strings/internal/cord_internal.h"
+#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_flat.h"
 #include "absl/strings/internal/cord_rep_ring.h"
 #include "absl/strings/internal/cordz_info.h"
@@ -42,6 +43,8 @@ inline void PrintTo(const CordzStatistics& stats, std::ostream* s) {
 
 namespace {
 
+using ::testing::Ge;
+
 // Creates a flat of the specified allocated size
 CordRepFlat* Flat(size_t size) {
   // Round up to a tag size, as we are going to poke an exact tag size back into
@@ -134,8 +137,8 @@ size_t SizeOf(const CordRepRing* rep) {
 }
 
 // Computes fair share memory used in a naive 'we dare to recurse' way.
-size_t FairShare(CordRep* rep, size_t ref = 1) {
-  size_t self = 0, children = 0;
+double FairShareImpl(CordRep* rep, size_t ref) {
+  double self = 0.0, children = 0.0;
   ref *= rep->refcount.Get();
   if (rep->tag >= FLAT) {
     self = SizeOf(rep->flat());
@@ -143,22 +146,32 @@ size_t FairShare(CordRep* rep, size_t ref = 1) {
     self = SizeOf(rep->external());
   } else if (rep->tag == SUBSTRING) {
     self = SizeOf(rep->substring());
-    children = FairShare(rep->substring()->child, ref);
+    children = FairShareImpl(rep->substring()->child, ref);
+  } else if (rep->tag == BTREE) {
+    self = SizeOf(rep->btree());
+    for (CordRep*edge : rep->btree()->Edges()) {
+      children += FairShareImpl(edge, ref);
+    }
   } else if (rep->tag == RING) {
     self = SizeOf(rep->ring());
     rep->ring()->ForEach([&](CordRepRing::index_type i) {
-      self += FairShare(rep->ring()->entry_child(i));
+      self += FairShareImpl(rep->ring()->entry_child(i), 1);
     });
   } else if (rep->tag == CONCAT) {
     self = SizeOf(rep->concat());
-    children = FairShare(rep->concat()->left, ref) +
-               FairShare(rep->concat()->right, ref);
+    children = FairShareImpl(rep->concat()->left, ref) +
+               FairShareImpl(rep->concat()->right, ref);
   } else {
     assert(false);
   }
   return self / ref + children;
 }
 
+// Returns the fair share memory size from `ShareFhareImpl()` as a size_t.
+size_t FairShare(CordRep* rep, size_t ref = 1) {
+  return static_cast<size_t>(FairShareImpl(rep, ref));
+}
+
 // Samples the cord and returns CordzInfo::GetStatistics()
 CordzStatistics SampleCord(CordRep* rep) {
   InlineData cord(rep);
@@ -191,6 +204,7 @@ MATCHER_P(EqStatistics, stats, "Statistics equal expected values") {
   STATS_MATCHER_EXPECT_EQ(node_counts.concat);
   STATS_MATCHER_EXPECT_EQ(node_counts.substring);
   STATS_MATCHER_EXPECT_EQ(node_counts.ring);
+  STATS_MATCHER_EXPECT_EQ(node_counts.btree);
   STATS_MATCHER_EXPECT_EQ(estimated_memory_usage);
   STATS_MATCHER_EXPECT_EQ(estimated_fair_share_memory_usage);
 
@@ -424,6 +438,103 @@ TEST(CordzInfoStatisticsTest, SharedSubstringRing) {
   EXPECT_THAT(SampleCord(substring), EqStatistics(expected));
 }
 
+TEST(CordzInfoStatisticsTest, BtreeLeaf) {
+  ASSERT_THAT(CordRepBtree::kMaxCapacity, Ge(3));
+  RefHelper ref;
+  auto* flat1 = Flat(2000);
+  auto* flat2 = Flat(200);
+  auto* substr = Substring(flat2);
+  auto* external = External(3000);
+
+  CordRepBtree* tree = CordRepBtree::Create(flat1);
+  tree = CordRepBtree::Append(tree, substr);
+  tree = CordRepBtree::Append(tree, external);
+  size_t flat3_count = CordRepBtree::kMaxCapacity - 3;
+  size_t flat3_size = 0;
+  for (size_t i = 0; i < flat3_count; ++i) {
+    auto* flat3 = Flat(70);
+    flat3_size += SizeOf(flat3);
+    tree = CordRepBtree::Append(tree, flat3);
+  }
+  ref.NeedsUnref(tree);
+
+  CordzStatistics expected;
+  expected.size = tree->length;
+  expected.estimated_memory_usage = SizeOf(tree) + SizeOf(flat1) +
+                                    SizeOf(flat2) + SizeOf(substr) +
+                                    flat3_size + SizeOf(external);
+  expected.estimated_fair_share_memory_usage = expected.estimated_memory_usage;
+  expected.node_count = 1 + 3 + 1 + flat3_count;
+  expected.node_counts.flat = 2 + flat3_count;
+  expected.node_counts.flat_128 = flat3_count;
+  expected.node_counts.flat_256 = 1;
+  expected.node_counts.external = 1;
+  expected.node_counts.substring = 1;
+  expected.node_counts.btree = 1;
+
+  EXPECT_THAT(SampleCord(tree), EqStatistics(expected));
+}
+
+TEST(CordzInfoStatisticsTest, BtreeNodeShared) {
+  RefHelper ref;
+  static constexpr int leaf_count = 3;
+  const size_t flat3_count = CordRepBtree::kMaxCapacity - 3;
+  ASSERT_THAT(flat3_count, Ge(0));
+
+  CordRepBtree* tree = nullptr;
+  size_t mem_size = 0;
+  for (int i = 0; i < leaf_count; ++i) {
+    auto* flat1 = ref.Ref(Flat(2000), 9);
+    mem_size += SizeOf(flat1);
+    if (i == 0) {
+      tree = CordRepBtree::Create(flat1);
+    } else {
+      tree = CordRepBtree::Append(tree, flat1);
+    }
+
+    auto* flat2 = Flat(200);
+    auto* substr = Substring(flat2);
+    mem_size += SizeOf(flat2) + SizeOf(substr);
+    tree = CordRepBtree::Append(tree, substr);
+
+    auto* external = External(30);
+    mem_size += SizeOf(external);
+    tree = CordRepBtree::Append(tree, external);
+
+    for (size_t i = 0; i < flat3_count; ++i) {
+      auto* flat3 = Flat(70);
+      mem_size += SizeOf(flat3);
+      tree = CordRepBtree::Append(tree, flat3);
+    }
+
+    if (i == 0) {
+      mem_size += SizeOf(tree);
+    } else {
+      mem_size += SizeOf(tree->Edges().back()->btree());
+    }
+  }
+  ref.NeedsUnref(tree);
+
+  // Ref count: 2 for top (add 1), 5 for leaf 0 (add 4).
+  ref.Ref(tree, 1);
+  ref.Ref(tree->Edges().front(), 4);
+
+  CordzStatistics expected;
+  expected.size = tree->length;
+  expected.estimated_memory_usage = SizeOf(tree) + mem_size;
+  expected.estimated_fair_share_memory_usage = FairShare(tree);
+
+  expected.node_count = 1 + leaf_count * (1 + 3 + 1 + flat3_count);
+  expected.node_counts.flat = leaf_count * (2 + flat3_count);
+  expected.node_counts.flat_128 = leaf_count * flat3_count;
+  expected.node_counts.flat_256 = leaf_count;
+  expected.node_counts.external = leaf_count;
+  expected.node_counts.substring = leaf_count;
+  expected.node_counts.btree = 1 + leaf_count;
+
+  EXPECT_THAT(SampleCord(tree), EqStatistics(expected));
+}
+
 TEST(CordzInfoStatisticsTest, ThreadSafety) {
   Notification stop;
   static constexpr int kNumThreads = 8;
@@ -471,9 +582,15 @@ TEST(CordzInfoStatisticsTest, ThreadSafety) {
                 CordRep::Unref(cord.as_tree());
                 cord.set_inline_size(0);
               } else {
-                // 50/50 Ring or Flat coin toss
+                // Coin toss to 25% ring, 25% btree, and 50% flat.
                 CordRep* rep = Flat(256);
-                rep = (coin_toss(gen) != 0) ? CordRepRing::Create(rep) : rep;
+                if (coin_toss(gen) != 0) {
+                  if (coin_toss(gen) != 0) {
+                    rep = CordRepRing::Create(rep);
+                  } else {
+                    rep = CordRepBtree::Create(rep);
+                  }
+                }
                 cord.make_tree(rep);
 
                 // 50/50 sample
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_statistics.h b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_statistics.h
index e03c651e9c4..da4c7dbb8cf 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_statistics.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/cordz_statistics.h
@@ -40,6 +40,7 @@ struct CordzStatistics {
     size_t substring = 0;  // #substring reps
     size_t concat = 0;     // #concat reps
     size_t ring = 0;       // #ring buffer reps
+    size_t btree = 0;      // #btree reps
   };
 
   // The size of the cord in bytes. This matches the result of Cord::size().
@@ -61,6 +62,8 @@ struct CordzStatistics {
 
   // The total number of nodes referenced by this cord.
   // For ring buffer Cords, this includes the 'ring buffer' node.
+  // For btree Cords, this includes all 'CordRepBtree' tree nodes as well as all
+  // the substring, flat and external nodes referenced by the tree.
   // A value of 0 implies the property has not been recorded.
   int64_t node_count = 0;
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/internal/str_split_internal.h b/chromium/third_party/abseil-cpp/absl/strings/internal/str_split_internal.h
index 17c1bfe8d31..e7664216171 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/internal/str_split_internal.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/internal/str_split_internal.h
@@ -64,7 +64,7 @@ class ConvertibleToStringView {
   ConvertibleToStringView(const std::string& s)  // NOLINT(runtime/explicit)
       : value_(s) {}
 
-  // Matches rvalue strings and moves their data to a member.
+  // Disable conversion from rvalue strings.
   ConvertibleToStringView(std::string&& s) = delete;
   ConvertibleToStringView(const std::string&& s) = delete;
 
diff --git a/chromium/third_party/abseil-cpp/absl/strings/str_format.h b/chromium/third_party/abseil-cpp/absl/strings/str_format.h
index 01465107e10..4b05c70c233 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/str_format.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/str_format.h
@@ -536,8 +536,7 @@ using FormatArg = str_format_internal::FormatArgImpl;
 // The arguments are provided in an `absl::Span<const absl::FormatArg>`.
 // Each `absl::FormatArg` object binds to a single argument and keeps a
 // reference to it. The values used to create the `FormatArg` objects must
-// outlive this function call. (See `str_format_arg.h` for information on
-// the `FormatArg` class.)_
+// outlive this function call.
 //
 // Example:
 //
diff --git a/chromium/third_party/abseil-cpp/absl/strings/string_view.cc b/chromium/third_party/abseil-cpp/absl/strings/string_view.cc
index c5f5de936de..d596e08cde4 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/string_view.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/string_view.cc
@@ -78,8 +78,8 @@ std::ostream& operator<<(std::ostream& o, string_view piece) {
   return o;
 }
 
-string_view::size_type string_view::find(string_view s, size_type pos) const
-    noexcept {
+string_view::size_type string_view::find(string_view s,
+                                         size_type pos) const noexcept {
   if (empty() || pos > length_) {
     if (empty() && pos == 0 && s.empty()) return 0;
     return npos;
@@ -98,8 +98,8 @@ string_view::size_type string_view::find(char c, size_type pos) const noexcept {
   return result != nullptr ? result - ptr_ : npos;
 }
 
-string_view::size_type string_view::rfind(string_view s, size_type pos) const
-    noexcept {
+string_view::size_type string_view::rfind(string_view s,
+                                          size_type pos) const noexcept {
   if (length_ < s.length_) return npos;
   if (s.empty()) return std::min(length_, pos);
   const char* last = ptr_ + std::min(length_ - s.length_, pos) + s.length_;
@@ -108,8 +108,8 @@ string_view::size_type string_view::rfind(string_view s, size_type pos) const
 }
 
 // Search range is [0..pos] inclusive.  If pos == npos, search everything.
-string_view::size_type string_view::rfind(char c, size_type pos) const
-    noexcept {
+string_view::size_type string_view::rfind(char c,
+                                          size_type pos) const noexcept {
   // Note: memrchr() is not available on Windows.
   if (empty()) return npos;
   for (size_type i = std::min(pos, length_ - 1);; --i) {
@@ -121,9 +121,8 @@ string_view::size_type string_view::rfind(char c, size_type pos) const
   return npos;
 }
 
-string_view::size_type string_view::find_first_of(string_view s,
-                                                  size_type pos) const
-    noexcept {
+string_view::size_type string_view::find_first_of(
+    string_view s, size_type pos) const noexcept {
   if (empty() || s.empty()) {
     return npos;
   }
@@ -138,9 +137,8 @@ string_view::size_type string_view::find_first_of(string_view s,
   return npos;
 }
 
-string_view::size_type string_view::find_first_not_of(string_view s,
-                                                      size_type pos) const
-    noexcept {
+string_view::size_type string_view::find_first_not_of(
+    string_view s, size_type pos) const noexcept {
   if (empty()) return npos;
   // Avoid the cost of LookupTable() for a single-character search.
   if (s.length_ == 1) return find_first_not_of(s.ptr_[0], pos);
@@ -153,9 +151,8 @@ string_view::size_type string_view::find_first_not_of(string_view s,
   return npos;
 }
 
-string_view::size_type string_view::find_first_not_of(char c,
-                                                      size_type pos) const
-    noexcept {
+string_view::size_type string_view::find_first_not_of(
+    char c, size_type pos) const noexcept {
   if (empty()) return npos;
   for (; pos < length_; ++pos) {
     if (ptr_[pos] != c) {
@@ -180,9 +177,8 @@ string_view::size_type string_view::find_last_of(string_view s,
   return npos;
 }
 
-string_view::size_type string_view::find_last_not_of(string_view s,
-                                                     size_type pos) const
-    noexcept {
+string_view::size_type string_view::find_last_not_of(
+    string_view s, size_type pos) const noexcept {
   if (empty()) return npos;
   size_type i = std::min(pos, length_ - 1);
   if (s.empty()) return i;
@@ -198,9 +194,8 @@ string_view::size_type string_view::find_last_not_of(string_view s,
   return npos;
 }
 
-string_view::size_type string_view::find_last_not_of(char c,
-                                                     size_type pos) const
-    noexcept {
+string_view::size_type string_view::find_last_not_of(
+    char c, size_type pos) const noexcept {
   if (empty()) return npos;
   size_type i = std::min(pos, length_ - 1);
   for (;; --i) {
diff --git a/chromium/third_party/abseil-cpp/absl/strings/string_view.h b/chromium/third_party/abseil-cpp/absl/strings/string_view.h
index 1f14a758ae4..ea760526dad 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/string_view.h
+++ b/chromium/third_party/abseil-cpp/absl/strings/string_view.h
@@ -62,6 +62,12 @@ ABSL_NAMESPACE_END
 #define ABSL_INTERNAL_STRING_VIEW_MEMCMP memcmp
 #endif  // ABSL_HAVE_BUILTIN(__builtin_memcmp)
 
+#if defined(__cplusplus) && __cplusplus >= 201402L
+#define ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR constexpr
+#else
+#define ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR
+#endif
+
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 
@@ -185,14 +191,16 @@ class string_view {
           ABSL_ATTRIBUTE_LIFETIME_BOUND) noexcept
       // This is implemented in terms of `string_view(p, n)` so `str.size()`
       // doesn't need to be reevaluated after `ptr_` is set.
-      : string_view(str.data(), str.size()) {}
+      // The length check is also skipped since it is unnecessary and causes
+      // code bloat.
+      : string_view(str.data(), str.size(), SkipCheckLengthTag{}) {}
 
   // Implicit constructor of a `string_view` from NUL-terminated `str`. When
   // accepting possibly null strings, use `absl::NullSafeStringView(str)`
   // instead (see below).
+  // The length check is skipped since it is unnecessary and causes code bloat.
   constexpr string_view(const char* str)  // NOLINT(runtime/explicit)
-      : ptr_(str),
-        length_(str ? CheckLengthInternal(StrlenInternal(str)) : 0) {}
+      : ptr_(str), length_(str ? StrlenInternal(str) : 0) {}
 
   // Implicit constructor of a `string_view` from a `const char*` and length.
   constexpr string_view(const char* data, size_type len)
@@ -265,9 +273,7 @@ class string_view {
   // string_view::size()
   //
   // Returns the number of characters in the `string_view`.
-  constexpr size_type size() const noexcept {
-    return length_;
-  }
+  constexpr size_type size() const noexcept { return length_; }
 
   // string_view::length()
   //
@@ -334,7 +340,7 @@ class string_view {
   //
   // Removes the first `n` characters from the `string_view`. Note that the
   // underlying string is not changed, only the view.
-  void remove_prefix(size_type n) {
+  ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void remove_prefix(size_type n) {
     ABSL_HARDENING_ASSERT(n <= length_);
     ptr_ += n;
     length_ -= n;
@@ -344,7 +350,7 @@ class string_view {
   //
   // Removes the last `n` characters from the `string_view`. Note that the
   // underlying string is not changed, only the view.
-  void remove_suffix(size_type n) {
+  ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void remove_suffix(size_type n) {
     ABSL_HARDENING_ASSERT(n <= length_);
     length_ -= n;
   }
@@ -352,7 +358,7 @@ class string_view {
   // string_view::swap()
   //
   // Swaps this `string_view` with another `string_view`.
-  void swap(string_view& s) noexcept {
+  ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void swap(string_view& s) noexcept {
     auto t = *this;
     *this = s;
     s = t;
@@ -389,7 +395,7 @@ class string_view {
   // `n`) as another string_view. This function throws `std::out_of_bounds` if
   // `pos > size`.
   // Use absl::ClippedSubstr if you need a truncating substr operation.
-  constexpr string_view substr(size_type pos, size_type n = npos) const {
+  constexpr string_view substr(size_type pos = 0, size_type n = npos) const {
     return ABSL_PREDICT_FALSE(pos > length_)
                ? (base_internal::ThrowStdOutOfRange(
                       "absl::string_view::substr"),
@@ -413,31 +419,31 @@ class string_view {
 
   // Overload of `string_view::compare()` for comparing a substring of the
   // 'string_view` and another `absl::string_view`.
-  int compare(size_type pos1, size_type count1, string_view v) const {
+  constexpr int compare(size_type pos1, size_type count1, string_view v) const {
     return substr(pos1, count1).compare(v);
   }
 
   // Overload of `string_view::compare()` for comparing a substring of the
   // `string_view` and a substring of another `absl::string_view`.
-  int compare(size_type pos1, size_type count1, string_view v, size_type pos2,
-              size_type count2) const {
+  constexpr int compare(size_type pos1, size_type count1, string_view v,
+                        size_type pos2, size_type count2) const {
     return substr(pos1, count1).compare(v.substr(pos2, count2));
   }
 
   // Overload of `string_view::compare()` for comparing a `string_view` and a
-  // a different  C-style string `s`.
-  int compare(const char* s) const { return compare(string_view(s)); }
+  // a different C-style string `s`.
+  constexpr int compare(const char* s) const { return compare(string_view(s)); }
 
   // Overload of `string_view::compare()` for comparing a substring of the
   // `string_view` and a different string C-style string `s`.
-  int compare(size_type pos1, size_type count1, const char* s) const {
+  constexpr int compare(size_type pos1, size_type count1, const char* s) const {
     return substr(pos1, count1).compare(string_view(s));
   }
 
   // Overload of `string_view::compare()` for comparing a substring of the
   // `string_view` and a substring of a different C-style string `s`.
-  int compare(size_type pos1, size_type count1, const char* s,
-              size_type count2) const {
+  constexpr int compare(size_type pos1, size_type count1, const char* s,
+                        size_type count2) const {
     return substr(pos1, count1).compare(string_view(s, count2));
   }
 
@@ -454,48 +460,92 @@ class string_view {
   // within the `string_view`.
   size_type find(char c, size_type pos = 0) const noexcept;
 
+  // Overload of `string_view::find()` for finding a substring of a different
+  // C-style string `s` within the `string_view`.
+  size_type find(const char* s, size_type pos, size_type count) const {
+    return find(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::find()` for finding a different C-style string
+  // `s` within the `string_view`.
+  size_type find(const char* s, size_type pos = 0) const {
+    return find(string_view(s), pos);
+  }
+
   // string_view::rfind()
   //
   // Finds the last occurrence of a substring `s` within the `string_view`,
   // returning the position of the first character's match, or `npos` if no
   // match was found.
-  size_type rfind(string_view s, size_type pos = npos) const
-      noexcept;
+  size_type rfind(string_view s, size_type pos = npos) const noexcept;
 
   // Overload of `string_view::rfind()` for finding the last given character `c`
   // within the `string_view`.
   size_type rfind(char c, size_type pos = npos) const noexcept;
 
+  // Overload of `string_view::rfind()` for finding a substring of a different
+  // C-style string `s` within the `string_view`.
+  size_type rfind(const char* s, size_type pos, size_type count) const {
+    return rfind(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::rfind()` for finding a different C-style string
+  // `s` within the `string_view`.
+  size_type rfind(const char* s, size_type pos = npos) const {
+    return rfind(string_view(s), pos);
+  }
+
   // string_view::find_first_of()
   //
   // Finds the first occurrence of any of the characters in `s` within the
   // `string_view`, returning the start position of the match, or `npos` if no
   // match was found.
-  size_type find_first_of(string_view s, size_type pos = 0) const
-      noexcept;
+  size_type find_first_of(string_view s, size_type pos = 0) const noexcept;
 
   // Overload of `string_view::find_first_of()` for finding a character `c`
   // within the `string_view`.
-  size_type find_first_of(char c, size_type pos = 0) const
-      noexcept {
+  size_type find_first_of(char c, size_type pos = 0) const noexcept {
     return find(c, pos);
   }
 
+  // Overload of `string_view::find_first_of()` for finding a substring of a
+  // different C-style string `s` within the `string_view`.
+  size_type find_first_of(const char* s, size_type pos,
+                                    size_type count) const {
+    return find_first_of(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::find_first_of()` for finding a different C-style
+  // string `s` within the `string_view`.
+  size_type find_first_of(const char* s, size_type pos = 0) const {
+    return find_first_of(string_view(s), pos);
+  }
+
   // string_view::find_last_of()
   //
   // Finds the last occurrence of any of the characters in `s` within the
   // `string_view`, returning the start position of the match, or `npos` if no
   // match was found.
-  size_type find_last_of(string_view s, size_type pos = npos) const
-      noexcept;
+  size_type find_last_of(string_view s, size_type pos = npos) const noexcept;
 
   // Overload of `string_view::find_last_of()` for finding a character `c`
   // within the `string_view`.
-  size_type find_last_of(char c, size_type pos = npos) const
-      noexcept {
+  size_type find_last_of(char c, size_type pos = npos) const noexcept {
     return rfind(c, pos);
   }
 
+  // Overload of `string_view::find_last_of()` for finding a substring of a
+  // different C-style string `s` within the `string_view`.
+  size_type find_last_of(const char* s, size_type pos, size_type count) const {
+    return find_last_of(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::find_last_of()` for finding a different C-style
+  // string `s` within the `string_view`.
+  size_type find_last_of(const char* s, size_type pos = npos) const {
+    return find_last_of(string_view(s), pos);
+  }
+
   // string_view::find_first_not_of()
   //
   // Finds the first occurrence of any of the characters not in `s` within the
@@ -507,20 +557,51 @@ class string_view {
   // that is not `c` within the `string_view`.
   size_type find_first_not_of(char c, size_type pos = 0) const noexcept;
 
+  // Overload of `string_view::find_first_not_of()` for finding a substring of a
+  // different C-style string `s` within the `string_view`.
+  size_type find_first_not_of(const char* s, size_type pos,
+                              size_type count) const {
+    return find_first_not_of(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::find_first_not_of()` for finding a different
+  // C-style string `s` within the `string_view`.
+  size_type find_first_not_of(const char* s, size_type pos = 0) const {
+    return find_first_not_of(string_view(s), pos);
+  }
+
   // string_view::find_last_not_of()
   //
   // Finds the last occurrence of any of the characters not in `s` within the
   // `string_view`, returning the start position of the last non-match, or
   // `npos` if no non-match was found.
   size_type find_last_not_of(string_view s,
-                                          size_type pos = npos) const noexcept;
+                             size_type pos = npos) const noexcept;
 
   // Overload of `string_view::find_last_not_of()` for finding a character
   // that is not `c` within the `string_view`.
-  size_type find_last_not_of(char c, size_type pos = npos) const
-      noexcept;
+  size_type find_last_not_of(char c, size_type pos = npos) const noexcept;
+
+  // Overload of `string_view::find_last_not_of()` for finding a substring of a
+  // different C-style string `s` within the `string_view`.
+  size_type find_last_not_of(const char* s, size_type pos,
+                             size_type count) const {
+    return find_last_not_of(string_view(s, count), pos);
+  }
+
+  // Overload of `string_view::find_last_not_of()` for finding a different
+  // C-style string `s` within the `string_view`.
+  size_type find_last_not_of(const char* s, size_type pos = npos) const {
+    return find_last_not_of(string_view(s), pos);
+  }
 
  private:
+  // The constructor from std::string delegates to this constuctor.
+  // See the comment on that constructor for the rationale.
+  struct SkipCheckLengthTag {};
+  string_view(const char* data, size_type len, SkipCheckLengthTag) noexcept
+      : ptr_(data), length_(len) {}
+
   static constexpr size_type kMaxSize =
       (std::numeric_limits<difference_type>::max)();
 
@@ -596,6 +677,7 @@ std::ostream& operator<<(std::ostream& o, string_view piece);
 ABSL_NAMESPACE_END
 }  // namespace absl
 
+#undef ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR
 #undef ABSL_INTERNAL_STRING_VIEW_MEMCMP
 
 #endif  // ABSL_USES_STD_STRING_VIEW
diff --git a/chromium/third_party/abseil-cpp/absl/strings/string_view_test.cc b/chromium/third_party/abseil-cpp/absl/strings/string_view_test.cc
index 643af8f81b8..2c13dd1c146 100644
--- a/chromium/third_party/abseil-cpp/absl/strings/string_view_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/strings/string_view_test.cc
@@ -449,6 +449,24 @@ TEST(StringViewTest, STL2) {
   EXPECT_EQ(d.find('x', 4), absl::string_view::npos);
   EXPECT_EQ(e.find('x', 7), absl::string_view::npos);
 
+  EXPECT_EQ(a.find(b.data(), 1, 0), 1);
+  EXPECT_EQ(a.find(c.data(), 9, 0), 9);
+  EXPECT_EQ(a.find(c.data(), absl::string_view::npos, 0),
+            absl::string_view::npos);
+  EXPECT_EQ(b.find(c.data(), absl::string_view::npos, 0),
+            absl::string_view::npos);
+  // empty string nonsense
+  EXPECT_EQ(d.find(b.data(), 4, 0), absl::string_view::npos);
+  EXPECT_EQ(e.find(b.data(), 7, 0), absl::string_view::npos);
+
+  EXPECT_EQ(a.find(b.data(), 1), absl::string_view::npos);
+  EXPECT_EQ(a.find(c.data(), 9), 23);
+  EXPECT_EQ(a.find(c.data(), absl::string_view::npos), absl::string_view::npos);
+  EXPECT_EQ(b.find(c.data(), absl::string_view::npos), absl::string_view::npos);
+  // empty string nonsense
+  EXPECT_EQ(d.find(b.data(), 4), absl::string_view::npos);
+  EXPECT_EQ(e.find(b.data(), 7), absl::string_view::npos);
+
   EXPECT_EQ(a.rfind(b), 0);
   EXPECT_EQ(a.rfind(b, 1), 0);
   EXPECT_EQ(a.rfind(c), 23);
@@ -490,6 +508,14 @@ TEST(StringViewTest, STL2) {
   EXPECT_EQ(e.rfind('o'), absl::string_view::npos);
   EXPECT_EQ(d.rfind('o', 4), absl::string_view::npos);
   EXPECT_EQ(e.rfind('o', 7), absl::string_view::npos);
+
+  EXPECT_EQ(a.rfind(b.data(), 1, 0), 1);
+  EXPECT_EQ(a.rfind(c.data(), 22, 0), 22);
+  EXPECT_EQ(a.rfind(c.data(), 1, 0), 1);
+  EXPECT_EQ(a.rfind(c.data(), 0, 0), 0);
+  EXPECT_EQ(b.rfind(c.data(), 0, 0), 0);
+  EXPECT_EQ(d.rfind(b.data(), 4, 0), 0);
+  EXPECT_EQ(e.rfind(b.data(), 7, 0), 0);
 }
 
 // Continued from STL2
@@ -678,6 +704,7 @@ TEST(StringViewTest, STL2Substr) {
   EXPECT_EQ(a.substr(23, 3), c);
   EXPECT_EQ(a.substr(23, 99), c);
   EXPECT_EQ(a.substr(0), a);
+  EXPECT_EQ(a.substr(), a);
   EXPECT_EQ(a.substr(3, 2), "de");
   // empty string nonsense
   EXPECT_EQ(d.substr(0, 99), e);
@@ -1087,7 +1114,24 @@ TEST(StringViewTest, ConstexprCompiles) {
   EXPECT_EQ(sp_npos, -1);
 }
 
-TEST(StringViewTest, ConstexprSubstr) {
+constexpr char ConstexprMethodsHelper() {
+#if defined(__cplusplus) && __cplusplus >= 201402L
+  absl::string_view str("123", 3);
+  str.remove_prefix(1);
+  str.remove_suffix(1);
+  absl::string_view bar;
+  str.swap(bar);
+  return bar.front();
+#else
+  return '2';
+#endif
+}
+
+TEST(StringViewTest, ConstexprMethods) {
+  // remove_prefix, remove_suffix, swap
+  static_assert(ConstexprMethodsHelper() == '2', "");
+
+  // substr
   constexpr absl::string_view foobar("foobar", 6);
   constexpr absl::string_view foo = foobar.substr(0, 3);
   constexpr absl::string_view bar = foobar.substr(3);
diff --git a/chromium/third_party/abseil-cpp/absl/synchronization/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/synchronization/CMakeLists.txt
index e633d0bf531..605efe2d02d 100644
--- a/chromium/third_party/abseil-cpp/absl/synchronization/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/synchronization/CMakeLists.txt
@@ -95,7 +95,7 @@ absl_cc_test(
   DEPS
     absl::synchronization
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -108,7 +108,7 @@ absl_cc_test(
   DEPS
     absl::synchronization
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -122,7 +122,7 @@ absl_cc_test(
     absl::graphcycles_internal
     absl::core_headers
     absl::raw_logging_internal
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -154,7 +154,7 @@ absl_cc_test(
     absl::memory
     absl::raw_logging_internal
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -167,7 +167,7 @@ absl_cc_test(
   DEPS
     absl::synchronization
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -183,7 +183,7 @@ absl_cc_library(
     absl::config
     absl::strings
     absl::time
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -199,7 +199,7 @@ absl_cc_test(
     absl::synchronization
     absl::strings
     absl::time
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
diff --git a/chromium/third_party/abseil-cpp/absl/time/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/time/CMakeLists.txt
index 00bdd499c1f..f6ff8bd1274 100644
--- a/chromium/third_party/abseil-cpp/absl/time/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/time/CMakeLists.txt
@@ -102,7 +102,7 @@ absl_cc_library(
     absl::config
     absl::raw_logging_internal
     absl::time_zone
-    gmock
+    GTest::gmock
   TESTONLY
 )
 
@@ -124,5 +124,5 @@ absl_cc_test(
     absl::config
     absl::core_headers
     absl::time_zone
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/time/duration_test.cc b/chromium/third_party/abseil-cpp/absl/time/duration_test.cc
index a3617e744ae..b7209e1c0af 100644
--- a/chromium/third_party/abseil-cpp/absl/time/duration_test.cc
+++ b/chromium/third_party/abseil-cpp/absl/time/duration_test.cc
@@ -17,6 +17,7 @@
 #endif
 
 #include <chrono>  // NOLINT(build/c++11)
+#include <cfloat>
 #include <cmath>
 #include <cstdint>
 #include <ctime>
@@ -1390,6 +1391,14 @@ void VerifyApproxSameAsMul(double time_as_seconds, int* const misses) {
 // Seconds(point) returns a duration near point * Seconds(1.0). (They may
 // not be exactly equal due to fused multiply/add contraction.)
 TEST(Duration, ToDoubleSecondsCheckEdgeCases) {
+#if (defined(__i386__) || defined(_M_IX86)) && FLT_EVAL_METHOD != 0
+  // We're using an x87-compatible FPU, and intermediate operations can be
+  // performed with 80-bit floats. This means the edge cases are different than
+  // what we expect here, so just skip this test.
+  GTEST_SKIP()
+      << "Skipping the test because we detected x87 floating-point semantics";
+#endif
+
   constexpr uint32_t kTicksPerSecond = absl::time_internal::kTicksPerSecond;
   constexpr auto duration_tick = absl::time_internal::MakeDuration(0, 1u);
   int misses = 0;
diff --git a/chromium/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc b/chromium/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc
index 8039353e585..f2777d91ef0 100644
--- a/chromium/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc
+++ b/chromium/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc
@@ -43,6 +43,7 @@
 #include <memory>
 #include <sstream>
 #include <string>
+#include <utility>
 
 #include "absl/base/config.h"
 #include "absl/time/internal/cctz/include/cctz/civil_time.h"
@@ -576,14 +577,17 @@ bool TimeZoneInfo::Load(ZoneInfoSource* zip) {
 
 namespace {
 
+using FilePtr = std::unique_ptr<FILE, int (*)(FILE*)>;
+
 // fopen(3) adaptor.
-inline FILE* FOpen(const char* path, const char* mode) {
+inline FilePtr FOpen(const char* path, const char* mode) {
 #if defined(_MSC_VER)
   FILE* fp;
   if (fopen_s(&fp, path, mode) != 0) fp = nullptr;
-  return fp;
+  return FilePtr(fp, fclose);
 #else
-  return fopen(path, mode);  // TODO: Enable the close-on-exec flag.
+  // TODO: Enable the close-on-exec flag.
+  return FilePtr(fopen(path, mode), fclose);
 #endif
 }
 
@@ -611,11 +615,11 @@ class FileZoneInfoSource : public ZoneInfoSource {
 
  protected:
   explicit FileZoneInfoSource(
-      FILE* fp, std::size_t len = std::numeric_limits<std::size_t>::max())
-      : fp_(fp, fclose), len_(len) {}
+      FilePtr fp, std::size_t len = std::numeric_limits<std::size_t>::max())
+      : fp_(std::move(fp)), len_(len) {}
 
  private:
-  std::unique_ptr<FILE, int (*)(FILE*)> fp_;
+  FilePtr fp_;
   std::size_t len_;
 };
 
@@ -644,17 +648,9 @@ std::unique_ptr<ZoneInfoSource> FileZoneInfoSource::Open(
   path.append(name, pos, std::string::npos);
 
   // Open the zoneinfo file.
-  FILE* fp = FOpen(path.c_str(), "rb");
-  if (fp == nullptr) return nullptr;
-  std::size_t length = 0;
-  if (fseek(fp, 0, SEEK_END) == 0) {
-    long offset = ftell(fp);
-    if (offset >= 0) {
-      length = static_cast<std::size_t>(offset);
-    }
-    rewind(fp);
-  }
-  return std::unique_ptr<ZoneInfoSource>(new FileZoneInfoSource(fp, length));
+  auto fp = FOpen(path.c_str(), "rb");
+  if (fp.get() == nullptr) return nullptr;
+  return std::unique_ptr<ZoneInfoSource>(new FileZoneInfoSource(std::move(fp)));
 }
 
 class AndroidZoneInfoSource : public FileZoneInfoSource {
@@ -663,8 +659,9 @@ class AndroidZoneInfoSource : public FileZoneInfoSource {
   std::string Version() const override { return version_; }
 
  private:
-  explicit AndroidZoneInfoSource(FILE* fp, std::size_t len, const char* vers)
-      : FileZoneInfoSource(fp, len), version_(vers) {}
+  explicit AndroidZoneInfoSource(FilePtr fp, std::size_t len,
+                                 std::string version)
+      : FileZoneInfoSource(std::move(fp), len), version_(std::move(version)) {}
   std::string version_;
 };
 
@@ -676,7 +673,7 @@ std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
   // See Android's libc/tzcode/bionic.cpp for additional information.
   for (const char* tzdata : {"/data/misc/zoneinfo/current/tzdata",
                              "/system/usr/share/zoneinfo/tzdata"}) {
-    std::unique_ptr<FILE, int (*)(FILE*)> fp(FOpen(tzdata, "rb"), fclose);
+    auto fp = FOpen(tzdata, "rb");
     if (fp.get() == nullptr) continue;
 
     char hbuf[24];  // covers header.zonetab_offset too
@@ -703,7 +700,7 @@ std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
       if (strcmp(name.c_str() + pos, ebuf) == 0) {
         if (fseek(fp.get(), static_cast<long>(start), SEEK_SET) != 0) break;
         return std::unique_ptr<ZoneInfoSource>(new AndroidZoneInfoSource(
-            fp.release(), static_cast<std::size_t>(length), vers));
+            std::move(fp), static_cast<std::size_t>(length), vers));
       }
     }
   }
diff --git a/chromium/third_party/abseil-cpp/absl/time/time.h b/chromium/third_party/abseil-cpp/absl/time/time.h
index 48982df45a3..e9cbce84e25 100644
--- a/chromium/third_party/abseil-cpp/absl/time/time.h
+++ b/chromium/third_party/abseil-cpp/absl/time/time.h
@@ -182,18 +182,29 @@ class Duration {
 
   // Overloads that forward to either the int64_t or double overloads above.
   // Integer operands must be representable as int64_t.
-  template <typename T>
+  template <typename T, time_internal::EnableIfIntegral<T> = 0>
   Duration& operator*=(T r) {
     int64_t x = r;
     return *this *= x;
   }
-  template <typename T>
+
+  template <typename T, time_internal::EnableIfIntegral<T> = 0>
   Duration& operator/=(T r) {
     int64_t x = r;
     return *this /= x;
   }
-  Duration& operator*=(float r) { return *this *= static_cast<double>(r); }
-  Duration& operator/=(float r) { return *this /= static_cast<double>(r); }
+
+  template <typename T, time_internal::EnableIfFloat<T> = 0>
+  Duration& operator*=(T r) {
+    double x = r;
+    return *this *= x;
+  }
+
+  template <typename T, time_internal::EnableIfFloat<T> = 0>
+  Duration& operator/=(T r) {
+    double x = r;
+    return *this /= x;
+  }
 
   template <typename H>
   friend H AbslHashValue(H h, Duration d) {
@@ -392,12 +403,30 @@ constexpr Duration InfiniteDuration();
 //
 //   absl::Duration a = absl::Seconds(60);
 //   absl::Duration b = absl::Minutes(1);  // b == a
-constexpr Duration Nanoseconds(int64_t n);
-constexpr Duration Microseconds(int64_t n);
-constexpr Duration Milliseconds(int64_t n);
-constexpr Duration Seconds(int64_t n);
-constexpr Duration Minutes(int64_t n);
-constexpr Duration Hours(int64_t n);
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Nanoseconds(T n) {
+  return time_internal::FromInt64(n, std::nano{});
+}
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Microseconds(T n) {
+  return time_internal::FromInt64(n, std::micro{});
+}
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Milliseconds(T n) {
+  return time_internal::FromInt64(n, std::milli{});
+}
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Seconds(T n) {
+  return time_internal::FromInt64(n, std::ratio<1>{});
+}
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Minutes(T n) {
+  return time_internal::FromInt64(n, std::ratio<60>{});
+}
+template <typename T, time_internal::EnableIfIntegral<T> = 0>
+constexpr Duration Hours(T n) {
+  return time_internal::FromInt64(n, std::ratio<3600>{});
+}
 
 // Factory overloads for constructing `Duration` values from a floating-point
 // number of the unit indicated by the factory function's name. These functions
@@ -547,10 +576,20 @@ inline std::ostream& operator<<(std::ostream& os, Duration d) {
 // `ZeroDuration()`. Parses "inf" and "-inf" as +/- `InfiniteDuration()`.
 bool ParseDuration(absl::string_view dur_string, Duration* d);
 
-// Support for flag values of type Duration. Duration flags must be specified
-// in a format that is valid input for absl::ParseDuration().
+// AbslParseFlag()
+//
+// Parses a command-line flag string representation `text` into a a Duration
+// value. Duration flags must be specified in a format that is valid input for
+// `absl::ParseDuration()`.
 bool AbslParseFlag(absl::string_view text, Duration* dst, std::string* error);
+
+
+// AbslUnparseFlag()
+//
+// Unparses a Duration value into a command-line string representation using
+// the format specified by `absl::ParseDuration()`.
 std::string AbslUnparseFlag(Duration d);
+
 ABSL_DEPRECATED("Use AbslParseFlag() instead.")
 bool ParseFlag(const std::string& text, Duration* dst, std::string* error);
 ABSL_DEPRECATED("Use AbslUnparseFlag() instead.")
@@ -813,8 +852,12 @@ Time FromChrono(const std::chrono::system_clock::time_point& tp);
 //   // tp == std::chrono::system_clock::from_time_t(123);
 std::chrono::system_clock::time_point ToChronoTime(Time);
 
-// Support for flag values of type Time. Time flags must be specified in a
-// format that matches absl::RFC3339_full. For example:
+// AbslParseFlag()
+//
+// Parses the command-line flag string representation `text` into a Time value.
+// Time flags must be specified in a format that matches absl::RFC3339_full.
+//
+// For example:
 //
 //   --start_time=2016-01-02T03:04:05.678+08:00
 //
@@ -824,7 +867,13 @@ std::chrono::system_clock::time_point ToChronoTime(Time);
 // seconds/milliseconds/etc from the Unix epoch, use an absl::Duration flag
 // and add that duration to absl::UnixEpoch() to get an absl::Time.
 bool AbslParseFlag(absl::string_view text, Time* t, std::string* error);
+
+// AbslUnparseFlag()
+//
+// Unparses a Time value into a command-line string representation using
+// the format specified by `absl::ParseTime()`.
 std::string AbslUnparseFlag(Time t);
+
 ABSL_DEPRECATED("Use AbslParseFlag() instead.")
 bool ParseFlag(const std::string& text, Time* t, std::string* error);
 ABSL_DEPRECATED("Use AbslUnparseFlag() instead.")
@@ -1476,25 +1525,6 @@ T ToChronoDuration(Duration d) {
 
 }  // namespace time_internal
 
-constexpr Duration Nanoseconds(int64_t n) {
-  return time_internal::FromInt64(n, std::nano{});
-}
-constexpr Duration Microseconds(int64_t n) {
-  return time_internal::FromInt64(n, std::micro{});
-}
-constexpr Duration Milliseconds(int64_t n) {
-  return time_internal::FromInt64(n, std::milli{});
-}
-constexpr Duration Seconds(int64_t n) {
-  return time_internal::FromInt64(n, std::ratio<1>{});
-}
-constexpr Duration Minutes(int64_t n) {
-  return time_internal::FromInt64(n, std::ratio<60>{});
-}
-constexpr Duration Hours(int64_t n) {
-  return time_internal::FromInt64(n, std::ratio<3600>{});
-}
-
 constexpr bool operator<(Duration lhs, Duration rhs) {
   return time_internal::GetRepHi(lhs) != time_internal::GetRepHi(rhs)
              ? time_internal::GetRepHi(lhs) < time_internal::GetRepHi(rhs)
diff --git a/chromium/third_party/abseil-cpp/absl/types/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/types/CMakeLists.txt
index c356b2117da..d7e8614e0d8 100644
--- a/chromium/third_party/abseil-cpp/absl/types/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/types/CMakeLists.txt
@@ -69,7 +69,7 @@ absl_cc_test(
     absl::exception_testing
     absl::raw_logging_internal
     absl::test_instance_tracker
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -85,7 +85,7 @@ absl_cc_test(
     absl::exception_testing
     absl::raw_logging_internal
     absl::test_instance_tracker
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -99,7 +99,7 @@ absl_cc_test(
     absl::any
     absl::config
     absl::exception_safety_testing
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -136,7 +136,7 @@ absl_cc_test(
     absl::inlined_vector
     absl::hash_testing
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -156,7 +156,7 @@ absl_cc_test(
     absl::inlined_vector
     absl::hash_testing
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -222,7 +222,7 @@ absl_cc_test(
     absl::raw_logging_internal
     absl::strings
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -236,7 +236,7 @@ absl_cc_test(
     absl::optional
     absl::config
     absl::exception_safety_testing
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -258,7 +258,7 @@ absl_cc_library(
     absl::type_traits
     absl::strings
     absl::utility
-    gmock_main
+    GTest::gmock_main
   TESTONLY
 )
 
@@ -275,7 +275,7 @@ absl_cc_test(
   DEPS
     absl::conformance_testing
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -288,7 +288,7 @@ absl_cc_test(
   DEPS
     absl::conformance_testing
     absl::type_traits
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -324,7 +324,7 @@ absl_cc_test(
     absl::memory
     absl::type_traits
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_library(
@@ -350,7 +350,7 @@ absl_cc_test(
   DEPS
     absl::base
     absl::compare
-    gmock_main
+    GTest::gmock_main
 )
 
 absl_cc_test(
@@ -365,5 +365,5 @@ absl_cc_test(
     absl::config
     absl::exception_safety_testing
     absl::memory
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/absl/utility/CMakeLists.txt b/chromium/third_party/abseil-cpp/absl/utility/CMakeLists.txt
index e1edd19aa01..865b758f23e 100644
--- a/chromium/third_party/abseil-cpp/absl/utility/CMakeLists.txt
+++ b/chromium/third_party/abseil-cpp/absl/utility/CMakeLists.txt
@@ -40,5 +40,5 @@ absl_cc_test(
     absl::core_headers
     absl::memory
     absl::strings
-    gmock_main
+    GTest::gmock_main
 )
diff --git a/chromium/third_party/abseil-cpp/ci/cmake_common.sh b/chromium/third_party/abseil-cpp/ci/cmake_common.sh
index aec8a117174..51f310693ef 100644
--- a/chromium/third_party/abseil-cpp/ci/cmake_common.sh
+++ b/chromium/third_party/abseil-cpp/ci/cmake_common.sh
@@ -14,7 +14,7 @@
 
 # The commit of GoogleTest to be used in the CMake tests in this directory.
 # Keep this in sync with the commit in the WORKSPACE file.
-readonly ABSL_GOOGLETEST_COMMIT="8567b09290fe402cf01923e2131c5635b8ed851b"
+readonly ABSL_GOOGLETEST_COMMIT="8d51ffdfab10b3fba636ae69bc03da4b54f8c235"
 
 # Avoid depending on GitHub by looking for a cached copy of the commit first.
 if [[ -r "${KOKORO_GFILE_DIR:-}/distdir/${ABSL_GOOGLETEST_COMMIT}.zip" ]]; then
diff --git a/chromium/third_party/abseil-cpp/ci/cmake_install_test.sh b/chromium/third_party/abseil-cpp/ci/cmake_install_test.sh
index ffc6b5168d7..97ed8478e0e 100755
--- a/chromium/third_party/abseil-cpp/ci/cmake_install_test.sh
+++ b/chromium/third_party/abseil-cpp/ci/cmake_install_test.sh
@@ -36,8 +36,11 @@ for link_type in ${LINK_TYPE}; do
     --tmpfs=/abseil-cpp:exec \
     --workdir=/abseil-cpp \
     --cap-add=SYS_PTRACE \
+    -e "ABSL_GOOGLETEST_COMMIT=${ABSL_GOOGLETEST_COMMIT}" \
+    -e "ABSL_GOOGLETEST_DOWNLOAD_URL=${ABSL_GOOGLETEST_DOWNLOAD_URL}" \
     -e "LINK_TYPE=${link_type}" \
     --rm \
+    ${DOCKER_EXTRA_ARGS:-} \
     ${DOCKER_CONTAINER} \
     /bin/bash -c "cp -r /abseil-cpp-ro/* . && CMake/install_test_project/test.sh"
 done
diff --git a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_asan_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_asan_bazel.sh
index ffbb8327e73..5245933a5f2 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_asan_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_asan_bazel.sh
@@ -83,6 +83,7 @@ for std in ${STD}; do
           --copt="-fsanitize=undefined" \
           --copt="-fno-sanitize-blacklist" \
           --copt=-Werror \
+          --distdir="/bazel-distdir" \
           --keep_going \
           --linkopt="-fsanitize=address" \
           --linkopt="-fsanitize-link-c++-runtime" \
diff --git a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_bazel.sh
index f6a2221e8a0..e0fe653de71 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_bazel.sh
@@ -85,6 +85,7 @@ for std in ${STD}; do
             --copt=\"${exceptions_mode}\" \
             --copt=-Werror \
             --define=\"absl=1\" \
+            --distdir=\"/bazel-distdir\" \
             --keep_going \
             --show_timestamps \
             --test_env=\"GTEST_INSTALL_FAILURE_SIGNAL_HANDLER=1\" \
diff --git a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_tsan_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_tsan_bazel.sh
index e70e8214cd1..555f6b1c2a9 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_tsan_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libcxx_tsan_bazel.sh
@@ -81,6 +81,7 @@ for std in ${STD}; do
           --copt="-fsanitize=thread" \
           --copt="-fno-sanitize-blacklist" \
           --copt=-Werror \
+          --distdir="/bazel-distdir" \
           --keep_going \
           --linkopt="-fsanitize=thread" \
           --show_timestamps \
diff --git a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libstdcxx_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libstdcxx_bazel.sh
index 0986ff40ccf..36fdf82c1dc 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libstdcxx_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_clang-latest_libstdcxx_bazel.sh
@@ -25,7 +25,7 @@ if [[ -z ${ABSEIL_ROOT:-} ]]; then
 fi
 
 if [[ -z ${STD:-} ]]; then
-  STD="c++11 c++14 c++17 c++20"
+  STD="c++11 c++14 c++17"
 fi
 
 if [[ -z ${COMPILATION_MODE:-} ]]; then
@@ -78,6 +78,7 @@ for std in ${STD}; do
           --copt="${exceptions_mode}" \
           --copt=-Werror \
           --define="absl=1" \
+          --distdir="/bazel-distdir" \
           --keep_going \
           --linkopt="--gcc-toolchain=/usr/local" \
           --show_timestamps \
diff --git a/chromium/third_party/abseil-cpp/ci/linux_docker_containers.sh b/chromium/third_party/abseil-cpp/ci/linux_docker_containers.sh
index 1c29d9a1f17..32865b83482 100644
--- a/chromium/third_party/abseil-cpp/ci/linux_docker_containers.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_docker_containers.sh
@@ -16,6 +16,6 @@
 # Test scripts should source this file to get the identifiers.
 
 readonly LINUX_ALPINE_CONTAINER="gcr.io/google.com/absl-177019/alpine:20201026"
-readonly LINUX_CLANG_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20201008"
-readonly LINUX_GCC_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20201008"
-readonly LINUX_GCC_FLOOR_CONTAINER="gcr.io/google.com/absl-177019/linux_gcc-floor:20201015"
+readonly LINUX_CLANG_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20210617"
+readonly LINUX_GCC_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20210617"
+readonly LINUX_GCC_FLOOR_CONTAINER="gcr.io/google.com/absl-177019/linux_gcc-floor:20210617"
diff --git a/chromium/third_party/abseil-cpp/ci/linux_gcc-floor_libstdcxx_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_gcc-floor_libstdcxx_bazel.sh
index 224aef81cbe..54ab68a37e2 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_gcc-floor_libstdcxx_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_gcc-floor_libstdcxx_bazel.sh
@@ -77,6 +77,7 @@ for std in ${STD}; do
           --copt="${exceptions_mode}" \
           --copt=-Werror \
           --define="absl=1" \
+          --distdir="/bazel-distdir" \
           --keep_going \
           --show_timestamps \
           --test_env="GTEST_INSTALL_FAILURE_SIGNAL_HANDLER=1" \
diff --git a/chromium/third_party/abseil-cpp/ci/linux_gcc-latest_libstdcxx_bazel.sh b/chromium/third_party/abseil-cpp/ci/linux_gcc-latest_libstdcxx_bazel.sh
index 37d89d9f829..0555ecedb5d 100755
--- a/chromium/third_party/abseil-cpp/ci/linux_gcc-latest_libstdcxx_bazel.sh
+++ b/chromium/third_party/abseil-cpp/ci/linux_gcc-latest_libstdcxx_bazel.sh
@@ -83,6 +83,7 @@ for std in ${STD}; do
             --copt=\"${exceptions_mode}\" \
             --copt=-Werror \
             --define=\"absl=1\" \
+            --distdir=\"/bazel-distdir\" \
             --keep_going \
             --show_timestamps \
             --test_env=\"GTEST_INSTALL_FAILURE_SIGNAL_HANDLER=1\" \
diff --git a/chromium/third_party/abseil-cpp/create_lts.py b/chromium/third_party/abseil-cpp/create_lts.py
index 302812addbb..d5d7b28c204 100755
--- a/chromium/third_party/abseil-cpp/create_lts.py
+++ b/chromium/third_party/abseil-cpp/create_lts.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright 2021 The Abseil Authors.
 #
diff --git a/chromium/third_party/abseil-cpp/generate_def_files.py b/chromium/third_party/abseil-cpp/generate_def_files.py
index 82d927688de..f288c9bfbad 100755
--- a/chromium/third_party/abseil-cpp/generate_def_files.py
+++ b/chromium/third_party/abseil-cpp/generate_def_files.py
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-
-# NOTE: This script requires python 3.
+#!/usr/bin/env python3
 
 """Script to generate Chromium's Abseil .def files at roll time.
 
@@ -16,7 +14,7 @@ Unless you are on a Windows machine, you need to set up your Chromium
 checkout for cross-compilation by following the instructions at
 https://chromium.googlesource.com/chromium/src.git/+/main/docs/win_cross.md.
 If you are on Windows, you may need to tweak this script to run, e.g. by
-changing "gn" to "gn.bat", changing "llvm-nm-9" to the name of your copy of
+changing "gn" to "gn.bat", changing "llvm-nm" to the name of your copy of
 llvm-nm, etc.
 """
 
@@ -71,7 +69,7 @@ def _GenerateDefFile(cpu, is_debug, extra_gn_args=[], suffix=None):
 
   gn = 'gn'
   autoninja = 'autoninja'
-  symbol_dumper = ['llvm-nm-9']
+  symbol_dumper = ['third_party/llvm-build/Release+Asserts/bin/llvm-nm']
   if sys.platform == 'win32':
     gn = 'gn.bat'
     autoninja = 'autoninja.bat'
diff --git a/chromium/third_party/abseil-cpp/roll_abseil.py b/chromium/third_party/abseil-cpp/roll_abseil.py
index 6d54e4f47ce..365b4602900 100755
--- a/chromium/third_party/abseil-cpp/roll_abseil.py
+++ b/chromium/third_party/abseil-cpp/roll_abseil.py
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-
-# NOTE: This script requires python 3.
+#!/usr/bin/env python3
 
 """Script to do the first step of Abseil roll into chromium.
 """
diff --git a/chromium/third_party/abseil-cpp/symbols_arm64_dbg.def b/chromium/third_party/abseil-cpp/symbols_arm64_dbg.def
index b67d1bd0e74..6755815b382 100644
--- a/chromium/third_party/abseil-cpp/symbols_arm64_dbg.def
+++ b/chromium/third_party/abseil-cpp/symbols_arm64_dbg.def
@@ -1,6 +1,7 @@
 EXPORTS
     ??$?0$$CBD$0A@@VoidPtr@str_format_internal@absl@@QEAA@PEBD@Z
     ??$?0$$CBU?$atomic@_N@__1@std@@@Condition@absl@@QEAA@P6A_NPEBU?$atomic@_N@__1@std@@@Z0@Z
+    ??$?0$$CBUCordRep@cord_internal@absl@@@Hex@absl@@QEAA@PEBUCordRep@cord_internal@1@W4PadSpec@1@@Z
     ??$?0$$CBVFormatArgImpl@str_format_internal@absl@@$$CBV012@@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@V?$initializer_list@VFormatArgImpl@str_format_internal@absl@@@std@@@Z
     ??$?0$$T@?$Storage@PEAH$00$0A@@internal_compressed_tuple@container_internal@absl@@QEAA@Uin_place_t@3@$$QEA$$T@Z
     ??$?0$$T@?$Storage@PEAPEAUCordRep@cord_internal@absl@@$00$0A@@internal_compressed_tuple@container_internal@absl@@QEAA@Uin_place_t@3@$$QEA$$T@Z
@@ -52,7 +53,6 @@ EXPORTS
     ??$?0AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@X@?$__compressed_pair_elem@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@$0A@$0A@@__1@std@@QEAA@AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@Z
     ??$?0AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@12@@?$__compressed_pair@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@@__1@std@@QEAA@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@12@$$QEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@12@@Z
     ??$?0AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@X@?$__compressed_pair_elem@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@$0A@$0A@@__1@std@@QEAA@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@12@@Z
-    ??$?0AEAPEAUCordRep@cord_internal@absl@@AEAPEAU012@$0A@@?$pair@PEAUCordRep@cord_internal@absl@@PEAU123@@__1@std@@QEAA@AEAPEAUCordRep@cord_internal@absl@@0@Z
     ??$?0AEAPEAUThreadIdentity@base_internal@absl@@AEBQ6AXPEAX@Z@?$__compressed_pair@PEAUThreadIdentity@base_internal@absl@@P6AXPEAX@Z@__1@std@@QEAA@AEAPEAUThreadIdentity@base_internal@absl@@AEBQ6AXPEAX@Z@Z
     ??$?0AEAPEAUThreadIdentity@base_internal@absl@@X@?$__compressed_pair_elem@PEAUThreadIdentity@base_internal@absl@@$0A@$0A@@__1@std@@QEAA@AEAPEAUThreadIdentity@base_internal@absl@@@Z
     ??$?0AEAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U__default_init_tag@__1@std@@@?$__compressed_pair@PEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAA@AEAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$QEAU__default_init_tag@12@@Z
@@ -221,7 +221,19 @@ EXPORTS
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAPEBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAPEBD@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAH$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
-    ??$?XH@Duration@absl@@QEAAAEAV01@H@Z
+    ??$?XH$0A@@Duration@absl@@QEAAAEAV01@H@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AEAAXPEAUCordRep@12@@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AEAAXV?$Span@QEAUCordRep@cord_internal@absl@@@2@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AEAAXPEAUCordRep@12@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AEAAXV?$Span@QEAUCordRep@cord_internal@absl@@@2@@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$AddEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -350,6 +362,8 @@ EXPORTS
     ??$HidePtr@$$CBX@base_internal@absl@@YA_KPEBX@Z
     ??$HidePtr@U?$atomic@_J@__1@std@@@base_internal@absl@@YA_KPEAU?$atomic@_J@__1@std@@@Z
     ??$HidePtr@X@base_internal@absl@@YA_KPEAX@Z
+    ??$Hours@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Init@$0A@@CordRepBtreeNavigator@cord_internal@absl@@AEAAPEAUCordRep@12@PEAVCordRepBtree@12@@Z
     ??$Init@H@FormatArgImpl@str_format_internal@absl@@AEAAXAEBH@Z
     ??$Initialize@V?$CopyValueAdapter@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@@?$Storage@PEAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXV?$CopyValueAdapter@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@12@_K@Z
     ??$Invoke@A6AXXZ$$V@Callable@base_internal@absl@@SAXA6AXXZ@Z
@@ -365,7 +379,19 @@ EXPORTS
     ??$MakeSpan@$SI$0CIA@@absl@@YA?AV?$Span@I@0@AEAY0CIA@I@Z
     ??$MakeSpan@$SI$0IA@@absl@@YA?AV?$Span@I@0@AEAY0IA@I@Z
     ??$MakeSpan@$SVFormatArgImpl@str_format_internal@absl@@@absl@@YA?AV?$Span@VFormatArgImpl@str_format_internal@absl@@@0@PEAVFormatArgImpl@str_format_internal@0@_K@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Microseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Microseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Milliseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Milliseconds@K$0A@@absl@@YA?AVDuration@0@K@Z
     ??$Milliseconds@N$0A@@absl@@YA?AVDuration@0@N@Z
+    ??$Minutes@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Nanoseconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QEBA_KXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00@absl@@U?$integer_sequence@_K$0A@$00$01@5@@internal_layout@container_internal@absl@@QEBA_KXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@@absl@@U?$integer_sequence@_K$0A@$00@5@@internal_layout@container_internal@absl@@QEBA_KXZ
@@ -395,6 +421,11 @@ EXPORTS
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitialized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
+    ??$Seconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Seconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Seconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$SharedCompareImpl@VCord@absl@@@absl@@YAHAEBVCord@0@0@Z
     ??$SharedCompareImpl@Vstring_view@absl@@@absl@@YAHAEBVCord@0@AEBVstring_view@0@@Z
     ??$StrAppend@$$V@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@0@1111@Z
@@ -641,7 +672,6 @@ EXPORTS
     ??$forward@AEAPEAPEBUCordRep@cord_internal@absl@@@__1@std@@YAAEAPEAPEBUCordRep@cord_internal@absl@@AEAPEAPEBU234@@Z
     ??$forward@AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@YAAEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEAPEAPEBV23456@@Z
     ??$forward@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@YAAEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@01@AEAPEAU201@@Z
-    ??$forward@AEAPEAUCordRep@cord_internal@absl@@@__1@std@@YAAEAPEAUCordRep@cord_internal@absl@@AEAPEAU234@@Z
     ??$forward@AEAPEAUPayload@status_internal@absl@@@__1@std@@YAAEAPEAUPayload@status_internal@absl@@AEAPEAU234@@Z
     ??$forward@AEAPEAUSubRange@absl@@@__1@std@@YAAEAPEAUSubRange@absl@@AEAPEAU23@@Z
     ??$forward@AEAPEAUThreadIdentity@base_internal@absl@@@__1@std@@YAAEAPEAUThreadIdentity@base_internal@absl@@AEAPEAU234@@Z
@@ -743,7 +773,6 @@ EXPORTS
     ??$get@Vstring_view@absl@@V12@@?$__get_pair@$0A@@__1@std@@SAAEBVstring_view@absl@@AEBU?$pair@Vstring_view@absl@@V12@@12@@Z
     ??$invoke@A6AXXZ$$V@base_internal@absl@@YAXA6AXXZ@Z
     ??$lower_bound@PEBUTransition@cctz@time_internal@absl@@U1234@UByUnixTime@1234@@__1@std@@YAPEBUTransition@cctz@time_internal@absl@@PEBU2345@0AEBU2345@UByUnixTime@2345@@Z
-    ??$make_pair@AEAPEAUCordRep@cord_internal@absl@@AEAPEAU123@@__1@std@@YA?AU?$pair@PEAUCordRep@cord_internal@absl@@PEAU123@@01@AEAPEAUCordRep@cord_internal@absl@@0@Z
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$V@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@XZ
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@AEAV12@@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@Z
     ??$max_size@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@X@?$allocator_traits@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@SA_KAEBV?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@12@@Z
@@ -780,6 +809,7 @@ EXPORTS
     ??$move@AEAUTransition@cctz@time_internal@absl@@@__1@std@@YA$$QEAUTransition@cctz@time_internal@absl@@AEAU2345@@Z
     ??$move@AEAUTransitionType@cctz@time_internal@absl@@@__1@std@@YA$$QEAUTransitionType@cctz@time_internal@absl@@AEAU2345@@Z
     ??$move@AEAUViableSubstitution@strings_internal@absl@@@__1@std@@YA$$QEAUViableSubstitution@strings_internal@absl@@AEAU234@@Z
+    ??$move@AEAV?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@@__1@std@@YA$$QEAV?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@AEAV23@@Z
     ??$move@AEAV?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@01@AEAV201@@Z
     ??$move@AEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@01@AEAV201@@Z
     ??$move@AEAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AEAV201@@Z
@@ -841,7 +871,9 @@ EXPORTS
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@PEBVFormatArgImpl@str_format_internal@1@_K@Z
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@XZ
     ??0?$Span@D@absl@@QEAA@PEAD_K@Z
+    ??0?$Span@D@absl@@QEAA@XZ
     ??0?$Span@I@absl@@QEAA@PEAI_K@Z
+    ??0?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEAA@PEBQEAUCordRep@cord_internal@1@_K@Z
     ??0?$Span@QEAX@absl@@QEAA@PEBQEAX_K@Z
     ??0?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@PEAVFormatArgImpl@str_format_internal@1@_K@Z
     ??0?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAA@XZ
@@ -992,6 +1024,7 @@ EXPORTS
     ??0?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
     ??0?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
     ??0?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
+    ??0AlphaNum@absl@@QEAA@H@Z
     ??0AlphaNum@absl@@QEAA@PEBD@Z
     ??0AlphaNum@absl@@QEAA@UDec@1@@Z
     ??0AlphaNum@absl@@QEAA@UHex@1@@Z
@@ -1002,6 +1035,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QEAA@PEBX@Z
     ??0Arg@substitute_internal@absl@@QEAA@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QEAA@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@$$QEAV01@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@AEBV01@@Z
     ??0BadStatusOrAccess@absl@@QEAA@VStatus@1@@Z
     ??0BlockingCounter@absl@@QEAA@H@Z
     ??0BoundConversion@str_format_internal@absl@@QEAA@XZ
@@ -1024,11 +1059,13 @@ EXPORTS
     ??0Cord@absl@@QEAA@XZ
     ??0CordForest@absl@@QEAA@_K@Z
     ??0CordRep@cord_internal@absl@@QEAA@XZ
+    ??0CordRepBtree@cord_internal@absl@@AEAA@XZ
+    ??0CordRepBtreeNavigator@cord_internal@absl@@QEAA@XZ
+    ??0CordRepBtreeReader@cord_internal@absl@@QEAA@XZ
     ??0CordRepConcat@cord_internal@absl@@QEAA@XZ
     ??0CordRepExternal@cord_internal@absl@@QEAA@XZ
     ??0CordRepFlat@cord_internal@absl@@QEAA@XZ
     ??0CordRepRing@cord_internal@absl@@AEAA@I@Z
-    ??0CordRepRingReader@cord_internal@absl@@QEAA@XZ
     ??0CordRepSubstring@cord_internal@absl@@QEAA@XZ
     ??0CordzHandle@cord_internal@absl@@IEAA@_N@Z
     ??0CordzHandle@cord_internal@absl@@QEAA@XZ
@@ -1045,9 +1082,10 @@ EXPORTS
     ??0FormatConversionSpecImpl@str_format_internal@absl@@QEAA@XZ
     ??0FormatSinkImpl@str_format_internal@absl@@QEAA@VFormatRawSinkImpl@12@@Z
     ??0GraphCycles@synchronization_internal@absl@@QEAA@XZ
-    ??0GroupPortableImpl@container_internal@absl@@QEAA@PEBC@Z
+    ??0GroupPortableImpl@container_internal@absl@@QEAA@PEBW4ctrl_t@12@@Z
     ??0HashtablezInfo@container_internal@absl@@QEAA@XZ
     ??0HashtablezSampler@container_internal@absl@@QEAA@XZ
+    ??0Hex@absl@@AEAA@W4PadSpec@1@_K@Z
     ??0Impl@time_zone@cctz@time_internal@absl@@AEAA@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??0InlineData@cord_internal@absl@@QEAA@W4DefaultInitType@012@@Z
     ??0InlineData@cord_internal@absl@@QEAA@XZ
@@ -1076,6 +1114,7 @@ EXPORTS
     ??0SpinLock@base_internal@absl@@QEAA@W4SchedulingMode@12@@Z
     ??0SpinLockHolder@base_internal@absl@@QEAA@PEAVSpinLock@12@@Z
     ??0Status@absl@@QEAA@$$QEAV01@@Z
+    ??0Status@absl@@QEAA@AEBV01@@Z
     ??0Status@absl@@QEAA@W4StatusCode@1@Vstring_view@1@@Z
     ??0StatusRep@status_internal@absl@@QEAA@W4StatusCode@2@Vstring_view@2@V?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@Z
     ??0Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEAA@_KAEBV?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@Z
@@ -1118,6 +1157,8 @@ EXPORTS
     ??0int128@absl@@QEAA@M@Z
     ??0int128@absl@@QEAA@N@Z
     ??0int128@absl@@QEAA@O@Z
+    ??0once_flag@absl@@QEAA@XZ
+    ??0string_view@absl@@AEAA@PEBD_KUSkipCheckLengthTag@01@@Z
     ??0string_view@absl@@QEAA@PEBD@Z
     ??0string_view@absl@@QEAA@PEBD_K@Z
     ??0string_view@absl@@QEAA@XZ
@@ -1241,12 +1282,15 @@ EXPORTS
     ??4?$optional@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@absl@@QEAAAEAV01@$$QEAV01@@Z
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IEAAAEAV012@$$QEAV012@@Z
     ??4?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAAAEAV012@$$QEAV012@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@AEBV01@@Z
     ??4Cord@absl@@QEAAAEAV01@$$QEAV01@@Z
     ??4Cord@absl@@QEAAAEAV01@Vstring_view@1@@Z
     ??4CordzUpdateTracker@cord_internal@absl@@QEAAAEAV012@AEBV012@@Z
     ??4InlineRep@Cord@absl@@QEAAAEAV012@$$QEAV012@@Z
     ??4Payload@status_internal@absl@@QEAAAEAU012@$$QEAU012@@Z
     ??4Status@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4Status@absl@@QEAAAEAV01@AEBV01@@Z
     ??4int128@absl@@QEAAAEAV01@H@Z
     ??4uint128@absl@@QEAAAEAV01@H@Z
     ??4uint128@absl@@QEAAAEAV01@_J@Z
@@ -1303,6 +1347,7 @@ EXPORTS
     ??A?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAAEBUPayload@status_internal@1@_K@Z
     ??A?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAAEBVFormatArgImpl@str_format_internal@1@_K@Z
     ??A?$Span@I@absl@@QEBAAEAI_K@Z
+    ??A?$array@PEAUCordRep@cord_internal@absl@@$01@__1@std@@QEAAAEAPEAUCordRep@cord_internal@absl@@_K@Z
     ??A?$unique_ptr@$$BY0A@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@V?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@23@@__1@std@@QEBAAEAPEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@12@_K@Z
     ??A?$unordered_map@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAAEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@12@@Z
     ??A?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransition@cctz@time_internal@absl@@_K@Z
@@ -1317,7 +1362,7 @@ EXPORTS
     ??B?$unique_ptr@VTimeZoneIf@cctz@time_internal@absl@@U?$default_delete@VTimeZoneIf@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_NXZ
     ??B?$unique_ptr@VZoneInfoSource@cctz@time_internal@absl@@U?$default_delete@VZoneInfoSource@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_NXZ
     ??BCord@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ??BCordRepRingReader@cord_internal@absl@@QEBA_NXZ
+    ??BCordRepBtreeReader@cord_internal@absl@@QEBA_NXZ
     ??BTimeZone@absl@@QEBA?AVtime_zone@cctz@time_internal@1@XZ
     ??Bint128@absl@@QEBAEXZ
     ??Bint128@absl@@QEBANXZ
@@ -1441,6 +1486,7 @@ EXPORTS
     ??R<lambda_2>@?0???$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@0_K1@Z@QEBA?A?<auto>@@I@Z
     ??R<lambda_2>@?0???$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@0_K1@Z@QEBA?A?<auto>@@I@Z
     ??R<lambda_2>@?0??erase@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEAAPEAUPayload@status_internal@3@PEBU453@@Z@QEBA?A?<auto>@@XZ
+    ??R?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@QEBAXPEAUCordRep@cord_internal@1@_K1@Z
     ??R?$FunctionRef@$$A6AXV?$Span@I@absl@@@Z@absl@@QEBAXV?$Span@I@1@@Z
     ??R?$FunctionRef@$$A6AXVstring_view@absl@@@Z@absl@@QEBAXVstring_view@1@@Z
     ??R?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAXPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@Z
@@ -1465,7 +1511,6 @@ EXPORTS
     ??RByCivilTime@Transition@cctz@time_internal@absl@@QEBA_NAEBU1234@0@Z
     ??RByUnixTime@Transition@cctz@time_internal@absl@@QEBA_NAEBU1234@0@Z
     ??Sabsl@@YA?AVuint128@0@V10@@Z
-    ??Tabsl@@YA?AVuint128@0@V10@0@Z
     ??Uabsl@@YA?AVuint128@0@V10@0@Z
     ??Ustr_format_internal@absl@@YA?AW4Flags@01@W4201@0@Z
     ??XDuration@absl@@QEAAAEAV01@N@Z
@@ -1519,12 +1564,14 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPEBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AEAA?AV23@_K@Z
+    ?AdvanceBtree@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?AdvanceBytes@ChunkIterator@Cord@absl@@AEAAX_K@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AEAAX_K@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AEAAX_K@Z
-    ?AdvanceRing@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?AdvanceStack@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?Align@adl_barrier@internal_layout@container_internal@absl@@YA_K_K0@Z
+    ?AlignBegin@CordRepBtree@cord_internal@absl@@AEAAXXZ
+    ?AlignEnd@CordRepBtree@cord_internal@absl@@AEAAXXZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPEAX_K@Z
     ?AllocSize@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QEBA_KXZ
     ?AllocSize@CordRepRing@cord_internal@absl@@SA_K_K@Z
@@ -1543,6 +1590,8 @@ EXPORTS
     ?Append@Cord@absl@@QEAAX$$QEAV12@@Z
     ?Append@Cord@absl@@QEAAXAEBV12@@Z
     ?Append@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QEAAXVstring_view@3@@Z
@@ -1553,6 +1602,7 @@ EXPORTS
     ?AppendNode@CordForest@absl@@AEAAPEAUCordRep@cord_internal@2@PEAU342@0@Z
     ?AppendPack@str_format_internal@absl@@YAAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendText@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_KVstring_view@4@@Z
     ?AppendTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -1566,6 +1616,8 @@ EXPORTS
     ?AssertHeld@Mutex@absl@@QEBAXXZ
     ?AssertNotHeld@Mutex@absl@@QEBAXXZ
     ?AssertReaderHeld@Mutex@absl@@QEBAXXZ
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@_N@Z
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPEBV123@PEBV123@_N@Z
     ?AssignLargeString@Cord@absl@@AEAAAEAV12@$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?AssignNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PEAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAUPayload@status_internal@3@@Z
     ?AssignSlow@InlineRep@Cord@absl@@AEAAXAEBV123@@Z
@@ -1630,28 +1682,39 @@ EXPORTS
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@PEBUPayload@status_internal@absl@@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PEAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PEAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PEAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@USubRange@absl@@@__1@std@@V?$move_iterator@PEAUSubRange@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@USubRange@absl@@@__1@std@@PEAUSubRange@3@@Z
+    ?Consume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?ConsumePrefix@absl@@YA_NPEAVstring_view@1@V21@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPEBDPEBD0PEAUUnboundConversion@12@PEAH@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@D@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@W4FormatConversionChar@2@@Z
     ?ControlWord@base_internal@absl@@YAPEAU?$atomic@I@__1@std@@PEAVonce_flag@2@@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAC_K@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAW4ctrl_t@12@_K@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_NAEBUUnboundConversion@34@Vstring_view@4@@Z
-    ?ConvertSpecialToEmptyAndFullToDeleted@GroupPortableImpl@container_internal@absl@@QEBAXPEAC@Z
+    ?ConvertSpecialToEmptyAndFullToDeleted@GroupPortableImpl@container_internal@absl@@QEBAXPEAW4ctrl_t@23@@Z
+    ?Copy@CordRepBtree@cord_internal@absl@@AEBAPEAV123@XZ
     ?Copy@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@II_K@Z
+    ?CopyBeginTo@CordRepBtree@cord_internal@absl@@AEBAPEAV123@_K0@Z
     ?CopyCordToString@absl@@YAXAEBVCord@1@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
+    ?CopyRaw@CordRepBtree@cord_internal@absl@@AEBAPEAV123@XZ
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
     ?CopyTo@InlineRep@Cord@absl@@QEBAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@AEBAXPEAD@Z
+    ?CopyToEndFrom@CordRepBtree@cord_internal@absl@@AEBAPEAV123@_K0@Z
     ?Crash@Helper@internal_statusor@absl@@SAXAEBVStatus@3@@Z
+    ?Create@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K11@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPEAUThreadIdentity@base_internal@2@XZ
+    ?Current@CordRepBtreeNavigator@cord_internal@absl@@QEBAPEAUCordRep@23@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPEAUThreadIdentity@12@XZ
+    ?Data@CordRepBtree@cord_internal@absl@@QEBA?AVstring_view@3@_K@Z
     ?Data@CordRepFlat@cord_internal@absl@@QEAAPEADXZ
     ?Data@CordRepFlat@cord_internal@absl@@QEBAPEBDXZ
     ?DataLength@Header@TimeZoneInfo@cctz@time_internal@absl@@QEBA_K_K@Z
@@ -1670,6 +1733,7 @@ EXPORTS
     ?DecrementSynchSem@Mutex@absl@@CA_NPEAV12@PEAUPerThreadSynch@base_internal@2@VKernelTimeout@synchronization_internal@2@@Z
     ?DefaultArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@XZ
     ?DefaultStackUnwinder@absl@@YAHPEAPEAXPEAHHHPEBX1@Z
+    ?Delete@CordRepBtree@cord_internal@absl@@CAXPEAV123@@Z
     ?Delete@CordRepExternal@cord_internal@absl@@SAXPEAUCordRep@23@@Z
     ?Delete@CordRepFlat@cord_internal@absl@@SAXPEAUCordRep@23@@Z
     ?Delete@CordRepRing@cord_internal@absl@@CAXPEAV123@@Z
@@ -1680,10 +1744,14 @@ EXPORTS
     ?Description@TimeZoneInfo@cctz@time_internal@absl@@UEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Description@TimeZoneLibC@cctz@time_internal@absl@@UEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Destroy@CordRep@cord_internal@absl@@SAXPEAU123@@Z
+    ?Destroy@CordRepBtree@cord_internal@absl@@SAXPEAV123@@Z
     ?Destroy@CordRepRing@cord_internal@absl@@CAXPEAV123@@Z
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AEAAXXZ
     ?DestroyCordSlow@Cord@absl@@AEAAXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyTree@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QEAA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QEBA_NPEBV123@@Z
@@ -1722,9 +1790,18 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPEBX_J@Z@base_internal@absl@@CAXPEBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PEBDHPEAPEADPEAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PEBDHPEAPEADPEAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPEAXQEBQEAXQEAHHH_NP6AXPEBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QEBAPEAUCordRep@23@W4EdgeType@123@@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QEBAPEAUCordRep@23@_K@Z
+    ?EdgeData@CordRepBtree@cord_internal@absl@@SA?AVstring_view@3@PEBUCordRep@23@@Z
+    ?EdgeDataPtr@CordRepBtree@cord_internal@absl@@SAPEBDPEBUCordRep@23@@Z
+    ?Edges@CordRepBtree@cord_internal@absl@@QEBA?AV?$Span@QEAUCordRep@cord_internal@absl@@@3@XZ
+    ?Edges@CordRepBtree@cord_internal@absl@@QEBA?AV?$Span@QEAUCordRep@cord_internal@absl@@@3@_K0@Z
     ?EmplaceTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@AEBVInlineData@53@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmplaceTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmptyString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
@@ -1762,7 +1839,6 @@ EXPORTS
     ?Find@ByChar@absl@@QEBA?AVstring_view@2@V32@_K@Z
     ?Find@ByLength@absl@@QEBA?AVstring_view@2@V32@_K@Z
     ?Find@ByString@absl@@QEBA?AVstring_view@2@V32@_K@Z
-    ?Find@CordRepRing@cord_internal@absl@@QEBA?AUPosition@123@I_K@Z
     ?Find@CordRepRing@cord_internal@absl@@QEBA?AUPosition@123@_K@Z
     ?FindFlatStartPiece@InlineRep@Cord@absl@@QEBA?AVstring_view@3@XZ
     ?FindPath@GraphCycles@synchronization_internal@absl@@QEBAHUGraphId@23@0HQEAU423@@Z
@@ -1866,13 +1942,16 @@ EXPORTS
     ?GetAllocator@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@USubRange@absl@@@__1@std@@XZ
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AEAA?AV?$Span@D@3@_K@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QEBAD_K@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QEBAD_K@Z
     ?GetCond@WinHelper@Waiter@synchronization_internal@absl@@SAPEAU_RTL_CONDITION_VARIABLE@@PEAV234@@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QEBA?AUCordzStatistics@23@XZ
@@ -1956,28 +2035,34 @@ EXPORTS
     ?GetYearDay@absl@@YAHV?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@1@@Z
     ?Global@HashtablezSampler@container_internal@absl@@SAAEAV123@XZ
     ?GuaranteedEqual@Condition@absl@@SA_NPEBV12@0@Z
-    ?H1@container_internal@absl@@YA_K_KPEBC@Z
+    ?H1@container_internal@absl@@YA_K_KPEBW4ctrl_t@12@@Z
     ?HandleInvalidStatusCtorArg@Helper@internal_statusor@absl@@SAXPEAVStatus@3@@Z
     ?HasBeenNotifiedInternal@Notification@absl@@CA_NPEBU?$atomic@_N@__1@std@@@Z
     ?HasEdge@GraphCycles@synchronization_internal@absl@@QEBA_NUGraphId@23@0@Z
     ?HasNode@GraphCycles@synchronization_internal@absl@@QEAA_NUGraphId@23@@Z
-    ?HashSeed@container_internal@absl@@YA_KPEBC@Z
+    ?HashSeed@container_internal@absl@@YA_KPEBW4ctrl_t@12@@Z
     ?Head@CordzInfo@cord_internal@absl@@SAPEAV123@AEBVCordzSnapshot@23@@Z
     ?HexStringToBytes@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@@Z
     ?HideMask@base_internal@absl@@YA_KXZ
-    ?Hours@absl@@YA?AVDuration@1@_J@Z
     ?IDivDuration@absl@@YA_JVDuration@1@0PEAV21@@Z
     ?IDivDuration@time_internal@absl@@YA_J_NVDuration@2@1PEAV32@@Z
     ?In@Time@absl@@QEBA?AUBreakdown@12@VTimeZone@2@@Z
     ?InMillisecondsFromNow@KernelTimeout@synchronization_internal@absl@@AEBAKXZ
     ?Increment@Refcount@cord_internal@absl@@QEAAXXZ
     ?IncrementSynchSem@Mutex@absl@@CAXPEAV12@PEAUPerThreadSynch@base_internal@2@@Z
+    ?IndexBefore@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@U4123@_K@Z
+    ?IndexBeyond@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@_K@Z
+    ?IndexOf@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@_K@Z
     ?InfiniteDuration@absl@@YA?AVDuration@1@XZ
     ?InfiniteFuture@absl@@YA?AVTime@1@XZ
     ?InfinitePast@absl@@YA?AVTime@1@XZ
+    ?Init@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@PEAVCordRepBtree@23@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
+    ?InitFirst@CordRepBtreeNavigator@cord_internal@absl@@QEAAPEAUCordRep@23@PEAVCordRepBtree@23@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXAEBV123@@Z
+    ?InitInstance@CordRepBtree@cord_internal@absl@@AEAAXH_K0@Z
     ?InitTree@ChunkIterator@Cord@absl@@AEAAXPEAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@AEBAXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AEAAXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PEAUCordRepExternal@12@@Z
     ?InitializeData@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@AEAAPEAPEAUCordRep@cord_internal@3@XZ
@@ -1996,14 +2081,19 @@ EXPORTS
     ?InvalidGraphId@synchronization_internal@absl@@YA?AUGraphId@12@XZ
     ?IsAborted@absl@@YA_NAEBVStatus@1@@Z
     ?IsAlreadyExists@absl@@YA_NAEBVStatus@1@@Z
+    ?IsBtree@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsCancelled@absl@@YA_NAEBVStatus@1@@Z
+    ?IsConcat@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsCooperative@SpinLock@base_internal@absl@@CA_NW4SchedulingMode@23@@Z
+    ?IsDataEdge@CordRepBtree@cord_internal@absl@@SA_NPEBUCordRep@23@@Z
     ?IsDataLoss@absl@@YA_NAEBVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NAEBVStatus@1@@Z
     ?IsEmpty@Queue@CordzHandle@cord_internal@absl@@QEBA_NXZ
+    ?IsExternal@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsFailedPrecondition@absl@@YA_NAEBVStatus@1@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
+    ?IsFlat@CordRep@cord_internal@absl@@QEBA_NXZ
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
     ?IsImmortal@Refcount@cord_internal@absl@@QEBA_NXZ
     ?IsInfiniteDuration@time_internal@absl@@YA_NVDuration@2@@Z
     ?IsInlined@Status@absl@@CA_N_K@Z
@@ -2016,11 +2106,14 @@ EXPORTS
     ?IsPermissionDenied@absl@@YA_NAEBVStatus@1@@Z
     ?IsReachable@GraphCycles@synchronization_internal@absl@@QEBA_NUGraphId@23@0@Z
     ?IsResourceExhausted@absl@@YA_NAEBVStatus@1@@Z
+    ?IsRing@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsSame@InlineRep@Cord@absl@@QEBA_NAEBV123@@Z
+    ?IsSubstring@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsUnauthenticated@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnavailable@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnknown@absl@@YA_NAEBVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPEBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QEBA_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?IsValidCapacity@container_internal@absl@@YA_N_K@Z
     ?IsValidIndex@CordRepRing@cord_internal@absl@@AEBA_NI@Z
@@ -2073,10 +2166,8 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAEAVInlineData@23@AEBV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CA_KPEBUCordRep@cord_internal@2@@Z
-    ?Microseconds@absl@@YA?AVDuration@1@_J@Z
-    ?Milliseconds@absl@@YA?AVDuration@1@_J@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@0@Z
     ?Min@string_view@absl@@CA_K_K0@Z
-    ?Minutes@absl@@YA?AVDuration@1@_J@Z
     ?MovedFromRep@Status@absl@@CA_KXZ
     ?MovedFromString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AEAAXHPEBI@Z
@@ -2094,13 +2185,16 @@ EXPORTS
     ?Mutable@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@_K@Z
     ?MutexDelay@synchronization_internal@absl@@YAHHH@Z
     ?Name@Impl@time_zone@cctz@time_internal@absl@@QEBAAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ?Nanoseconds@absl@@YA?AVDuration@1@_J@Z
     ?NegateAndSubtractOne@time_internal@absl@@YA_J_J@Z
     ?Never@KernelTimeout@synchronization_internal@absl@@SA?AV123@XZ
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@H@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@0@Z
     ?New@CordRepFlat@cord_internal@absl@@SAPEAU123@_K@Z
     ?New@CordRepRing@cord_internal@absl@@CAPEAV123@_K0@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
+    ?Next@CordRepBtreeNavigator@cord_internal@absl@@QEAAPEAUCordRep@23@XZ
+    ?Next@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QEBAPEAV123@AEBVCordzSnapshot@23@@Z
     ?NextCapacity@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@SA_K_K@Z
     ?NextCapacity@?$Storage@PEAUCordRep@cord_internal@absl@@$01V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@SA_K_K@Z
@@ -2113,6 +2207,7 @@ EXPORTS
     ?NextTransition@TimeZone@absl@@QEBA_NVTime@2@PEAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
     ?NextTransition@TimeZoneLibC@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
+    ?NextUp@CordRepBtreeNavigator@cord_internal@absl@@AEAAPEAUCordRep@23@XZ
     ?NominalCPUFrequency@base_internal@absl@@YANXZ
     ?NormalizeLogSeverity@absl@@YA?AW4LogSeverity@1@W421@@Z
     ?NotFoundError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
@@ -2122,6 +2217,7 @@ EXPORTS
     ?Now@UnscaledCycleClockWrapperForGetCurrentTime@time_internal@absl@@SA_JXZ
     ?Now@absl@@YA?AVTime@1@XZ
     ?NumCPUs@base_internal@absl@@YAHXZ
+    ?NumClonedBytes@container_internal@absl@@YA_KXZ
     ?ODRCheck@CordzHandle@cord_internal@absl@@AEBAXXZ
     ?ODRCheck@CordzInfo@cord_internal@absl@@AEBAXXZ
     ?OccursBefore@ViableSubstitution@strings_internal@absl@@QEBA_NAEBU123@@Z
@@ -2157,10 +2253,13 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AEAAXXZ
     ?Prepend@Cord@absl@@QEAAXAEBV12@@Z
     ?Prepend@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
     ?PrependNode@CordForest@absl@@AEAAPEAUCordRep@cord_internal@2@PEAU342@0@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -2181,6 +2280,8 @@ EXPORTS
     ?Read1To3@MixingHashState@hash_internal@absl@@CAIPEBE_K@Z
     ?Read4To8@MixingHashState@hash_internal@absl@@CA_KPEBE_K@Z
     ?Read9To16@MixingHashState@hash_internal@absl@@CA?AU?$pair@_K_K@__1@std@@PEBE_K@Z
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUReadResult@123@_K0@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K0AEAPEAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QEAAHAEBUParsedFloat@23@H@Z
@@ -2194,6 +2295,7 @@ EXPORTS
     ?ReclaimThreadIdentity@synchronization_internal@absl@@YAXPEAX@Z
     ?RecordInsertSlow@container_internal@absl@@YAXPEAUHashtablezInfo@12@_K1@Z
     ?Ref@CordRep@cord_internal@absl@@SAPEAU123@PEAU123@@Z
+    ?Ref@Status@absl@@CAX_K@Z
     ?RefCordRep@CordzInfo@cord_internal@absl@@QEBAPEAUCordRep@23@XZ
     ?Register@CycleClockSource@base_internal@absl@@CAXP6A_JXZ@Z
     ?Register@HashtablezSampler@container_internal@absl@@QEAAPEAUHashtablezInfo@23@XZ
@@ -2221,19 +2323,19 @@ EXPORTS
     ?Reset@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
-    ?Reset@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@PEAVCordRepRing@23@@Z
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AEAA_NAEBV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResetToEmpty@InlineRep@Cord@absl@@AEAAXXZ
     ?Resize@?$ResizeUninitializedTraits@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@SAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?RoundUp@cord_internal@absl@@YA_K_K0@Z
     ?RoundUpForTag@cord_internal@absl@@YA_K_K@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QEBA_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPEBD_K@Z
     ?SampleSlow@container_internal@absl@@YAPEAUHashtablezInfo@12@PEA_J@Z
-    ?Seconds@absl@@YA?AVDuration@1@_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
+    ?Seek@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
     ?SetAllocatedData@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAH_K@Z
     ?SetAllocatedData@?$Storage@PEAUCordRep@cord_internal@absl@@$01V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAPEAUCordRep@cord_internal@3@_K@Z
     ?SetAllocatedData@?$Storage@PEAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAPEAUCordRep@cord_internal@3@_K@Z
@@ -2270,7 +2372,7 @@ EXPORTS
     ?SetWidth@FormatConversionSpecImplFriend@str_format_internal@absl@@SAXHPEAVFormatConversionSpecImpl@23@@Z
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QEAAXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QEAAXXZ
     ?SignalAll@CondVar@absl@@QEAAXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PEA_N@Z
@@ -2280,6 +2382,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SA_KXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
     ?SleepFor@absl@@YAXVDuration@1@@Z
     ?SlowLock@SpinLock@base_internal@absl@@AEAAXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AEAAXI@Z
@@ -2311,6 +2414,7 @@ EXPORTS
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@000@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@00@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@0@Z
+    ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@@Z
     ?StrReplaceAll@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@4@@Z
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?StripAsciiWhitespace@absl@@YA?AVstring_view@1@V21@@Z
@@ -2319,6 +2423,7 @@ EXPORTS
     ?StrlenInternal@string_view@absl@@CA_KPEBD@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AEAAXI_K@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@_K11@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QEAAPEAUCordRep@23@_K0@Z
     ?Subcord@Cord@absl@@QEBA?AV12@_K0@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PEBV62@_K@Z
     ?SubtractSize@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAX_K@Z
@@ -2389,6 +2494,7 @@ EXPORTS
     ?ToInt64Minutes@absl@@YA_JVDuration@1@@Z
     ?ToInt64Nanoseconds@absl@@YA_JVDuration@1@@Z
     ?ToInt64Seconds@absl@@YA_JVDuration@1@@Z
+    ?ToOpResult@CordRepBtree@cord_internal@absl@@AEAA?AUOpResult@123@_N@Z
     ?ToString@?$BigUnsigned@$03@strings_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@?$BigUnsigned@$0FE@@strings_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@Status@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4StatusToStringMode@2@@Z
@@ -2825,6 +2931,7 @@ EXPORTS
     ?back@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransition@cctz@time_internal@absl@@XZ
     ?back@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransitionType@cctz@time_internal@absl@@XZ
     ?back@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUViableSubstitution@strings_internal@absl@@XZ
+    ?back@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?base@?$__wrap_iter@PEAPEAVCordzHandle@cord_internal@absl@@@__1@std@@QEBAPEAPEAVCordzHandle@cord_internal@absl@@XZ
     ?base@?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@__1@std@@QEBAPEAUTransition@cctz@time_internal@absl@@XZ
     ?base@?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@__1@std@@QEBAPEAUTransitionType@cctz@time_internal@absl@@XZ
@@ -2838,6 +2945,7 @@ EXPORTS
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     ?begin@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAPEBUPayload@status_internal@2@XZ
     ?begin@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
+    ?begin@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?begin@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAA?AV?$__hash_iterator@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@23@XZ
     ?begin@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@XZ
     ?begin@?$initializer_list@PEAUCordRep@cord_internal@absl@@@std@@QEBAPEBQEAUCordRep@cord_internal@absl@@XZ
@@ -2851,8 +2959,13 @@ EXPORTS
     ?begin@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@23@XZ
     ?begin@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?begin@ChunkRange@Cord@absl@@QEBA?AVChunkIterator@23@XZ
+    ?begin@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?begin@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBAPEAPEAUCordRep@cord_internal@3@XZ
     ?begin@string_view@absl@@QEBAPEBDXZ
+    ?btree@CordRep@cord_internal@absl@@QEAAPEAVCordRepBtree@23@XZ
+    ?btree@CordRep@cord_internal@absl@@QEBAPEBVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeNavigator@cord_internal@absl@@QEBAPEAVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeReader@cord_internal@absl@@QEBAPEAVCordRepBtree@23@XZ
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     ?capacity@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEAV?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
@@ -2879,6 +2992,7 @@ EXPORTS
     ?capacity@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
+    ?capacity@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?capacity@CordRepRing@cord_internal@absl@@QEBAIXZ
     ?chunk_begin@Cord@absl@@QEBA?AVChunkIterator@12@XZ
     ?chunk_end@Cord@absl@@QEBA?AVChunkIterator@12@XZ
@@ -2907,9 +3021,9 @@ EXPORTS
     ?compare_exchange_weak@?$__atomic_base@PEAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QEAA_NAEAPEAUHashtablezInfo@container_internal@absl@@PEAU456@W4memory_order@23@2@Z
     ?concat@CordRep@cord_internal@absl@@QEAAPEAUCordRepConcat@23@XZ
     ?concat@CordRep@cord_internal@absl@@QEBAPEBUCordRepConcat@23@XZ
-    ?consumed@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
+    ?consumed@CordRepBtreeReader@cord_internal@absl@@QEBA_KXZ
     ?conversion_char@FormatConversionSpecImpl@str_format_internal@absl@@QEBA?AW4FormatConversionChar@3@XZ
-    ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cordz_info@InlineData@cord_internal@absl@@QEBAPEAVCordzInfo@23@XZ
     ?cordz_info@InlineRep@Cord@absl@@QEBAPEAVCordzInfo@cord_internal@3@XZ
     ?cordz_should_profile@cord_internal@absl@@YA_NXZ
@@ -2925,6 +3039,7 @@ EXPORTS
     ?data@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$Span@D@absl@@QEBAPEADXZ
     ?data@?$Span@I@absl@@QEBAPEAIXZ
+    ?data@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?data@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEAVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$vector@PEAUCordRep@cord_internal@absl@@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@__1@std@@QEBAPEBQEAUCordRep@cord_internal@absl@@XZ
     ?data@?$vector@PEAVCordzHandle@cord_internal@absl@@V?$allocator@PEAVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@QEBAPEBQEAVCordzHandle@cord_internal@absl@@XZ
@@ -3017,6 +3132,7 @@ EXPORTS
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEAAPEAUPayload@status_internal@2@XZ
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAPEBUPayload@status_internal@2@XZ
     ?end@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
+    ?end@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?end@?$__deque_base@PEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@IEAA?AV?$__deque_iterator@PEBVImpl@time_zone@cctz@time_internal@absl@@PEAPEBV12345@AEAPEBV12345@PEAPEAPEBV12345@_J$0A@@23@XZ
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     ?end@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@XZ
@@ -3029,6 +3145,7 @@ EXPORTS
     ?end@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@23@XZ
     ?end@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?end@ChunkRange@Cord@absl@@QEBA?AVChunkIterator@23@XZ
+    ?end@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?end@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBAPEAPEAUCordRep@cord_internal@3@XZ
     ?end@string_view@absl@@QEBAPEBDXZ
     ?entries@CordRepRing@cord_internal@absl@@QEBAIII@Z
@@ -3036,7 +3153,6 @@ EXPORTS
     ?entry_begin_pos@CordRepRing@cord_internal@absl@@QEBAAEB_KI@Z
     ?entry_child@CordRepRing@cord_internal@absl@@AEAAPEAPEAUCordRep@23@XZ
     ?entry_child@CordRepRing@cord_internal@absl@@QEBAAEBQEAUCordRep@23@I@Z
-    ?entry_data@CordRepRing@cord_internal@absl@@QEBA?AVstring_view@3@I@Z
     ?entry_data_offset@CordRepRing@cord_internal@absl@@AEAAPEAIXZ
     ?entry_data_offset@CordRepRing@cord_internal@absl@@QEBAAEBII@Z
     ?entry_end_offset@CordRepRing@cord_internal@absl@@QEBA_KI@Z
@@ -3049,6 +3165,7 @@ EXPORTS
     ?exchange@?$__atomic_base@P6AXAEBUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QEAAP6AXAEBUHashtablezInfo@container_internal@absl@@@ZP6AX0@ZW4memory_order@23@@Z
     ?external@CordRep@cord_internal@absl@@QEAAPEAUCordRepExternal@23@XZ
     ?external@CordRep@cord_internal@absl@@QEBAPEBUCordRepExternal@23@XZ
+    ?fetch_add_end@CordRepBtree@cord_internal@absl@@AEAA_K_K@Z
     ?find@?$unordered_map@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAA?AV?$__hash_map_iterator@V?$__hash_iterator@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@23@@Z
     ?find@string_view@absl@@QEBA_KD_K@Z
     ?find@string_view@absl@@QEBA_KV12@_K@Z
@@ -3170,9 +3287,11 @@ EXPORTS
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     ?head@CordRepRing@cord_internal@absl@@QEBAIXZ
     ?head@Filler@CordRepRing@cord_internal@absl@@QEBAIXZ
+    ?height@CordRepBtree@cord_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Uhour_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
+    ?index@CordRepBtree@cord_internal@absl@@QEBA_KW4EdgeType@123@@Z
     ?inline_size@InlineData@cord_internal@absl@@QEBA_KXZ
     ?inline_size@InlineRep@Cord@absl@@AEBA_KXZ
     ?is_basic@FormatConversionSpecImpl@str_format_internal@absl@@QEBA_NXZ
@@ -3189,7 +3308,7 @@ EXPORTS
     ?is_tree@InlineRep@Cord@absl@@QEBA_NXZ
     ?key_eq@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAAEAV?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@XZ
     ?length@?$Span@D@absl@@QEBA_KXZ
-    ?length@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
+    ?length@CordRepBtreeReader@cord_internal@absl@@QEBA_KXZ
     ?length@string_view@absl@@QEBA_KXZ
     ?load@?$__atomic_base@P6AXAEBUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QEBAP6AXAEBUHashtablezInfo@container_internal@absl@@@ZW4memory_order@23@@Z
     ?load@?$__atomic_base@PEAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QEBAPEAUHashtablezInfo@container_internal@absl@@W4memory_order@23@@Z
@@ -3304,7 +3423,6 @@ EXPORTS
     ?release@?$unique_ptr@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@@__1@std@@QEAAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@23@XZ
     ?release@?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@XZ
     ?release@?$unique_ptr@VTimeZoneInfo@cctz@time_internal@absl@@U?$default_delete@VTimeZoneInfo@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAVTimeZoneInfo@cctz@time_internal@absl@@XZ
-    ?remaining@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
     ?remove_prefix@InlineRep@Cord@absl@@QEAAX_K@Z
     ?remove_prefix@string_view@absl@@QEAAX_K@Z
     ?remove_suffix@string_view@absl@@QEAAX_K@Z
@@ -3328,7 +3446,6 @@ EXPORTS
     ?rfind@string_view@absl@@QEBA_KV12@_K@Z
     ?ring@CordRep@cord_internal@absl@@QEAAPEAVCordRepRing@23@XZ
     ?ring@CordRep@cord_internal@absl@@QEBAPEBVCordRepRing@23@XZ
-    ?ring@CordRepRingReader@cord_internal@absl@@QEBAPEAVCordRepRing@23@XZ
     ?safe_strto128_base@numbers_internal@absl@@YA_NVstring_view@2@PEAVint128@2@H@Z
     ?safe_strto32_base@numbers_internal@absl@@YA_NVstring_view@2@PEAHH@Z
     ?safe_strto64_base@numbers_internal@absl@@YA_NVstring_view@2@PEA_JH@Z
@@ -3379,11 +3496,13 @@ EXPORTS
     ?second@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?second@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?set_arg@BoundConversion@str_format_internal@absl@@QEAAXPEBVFormatArgImpl@23@@Z
+    ?set_begin@CordRepBtree@cord_internal@absl@@AEAAX_K@Z
     ?set_cordz_info@InlineData@cord_internal@absl@@QEAAXPEAVCordzInfo@23@@Z
     ?set_cordz_mean_interval@cord_internal@absl@@YAXH@Z
     ?set_data@InlineRep@Cord@absl@@QEAAPEAD_K@Z
     ?set_data@InlineRep@Cord@absl@@QEAAXPEBD_K_N@Z
     ?set_depth@CordRepConcat@cord_internal@absl@@QEAAXE@Z
+    ?set_end@CordRepBtree@cord_internal@absl@@AEAAX_K@Z
     ?set_from_arg@InputValue@UnboundConversion@str_format_internal@absl@@QEAAXH@Z
     ?set_inline_size@InlineData@cord_internal@absl@@QEAAX_K@Z
     ?set_inline_size@InlineRep@Cord@absl@@AEAAX_K@Z
@@ -3402,6 +3521,7 @@ EXPORTS
     ?size@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$Span@D@absl@@QEBA_KXZ
     ?size@?$Span@I@absl@@QEBA_KXZ
+    ?size@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QEAAAEA_KXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QEBA_KXZ
@@ -3423,6 +3543,7 @@ EXPORTS
     ?size@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?size@AlphaNum@absl@@QEBA_KXZ
     ?size@Cord@absl@@QEBA_KXZ
+    ?size@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?size@InlineRep@Cord@absl@@QEBA_KXZ
     ?size@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBA_KXZ
     ?size@string_view@absl@@QEBA_KXZ
@@ -3434,6 +3555,7 @@ EXPORTS
     ?store@?$__atomic_base@W4OnDeadlockCycle@absl@@$0A@@__1@std@@QEAAXW4OnDeadlockCycle@absl@@W4memory_order@23@@Z
     ?store@?$__atomic_base@W4State@PerThreadSynch@base_internal@absl@@$0A@@__1@std@@QEAAXW4State@PerThreadSynch@base_internal@absl@@W4memory_order@23@@Z
     ?str@UntypedFormatSpecImpl@str_format_internal@absl@@QEBA?AVstring_view@3@XZ
+    ?sub_fetch_begin@CordRepBtree@cord_internal@absl@@AEAA_K_K@Z
     ?substr@string_view@absl@@QEBA?AV12@_K0@Z
     ?substring@CordRep@cord_internal@absl@@QEAAPEAUCordRepSubstring@23@XZ
     ?substring@CordRep@cord_internal@absl@@QEBAPEBUCordRepSubstring@23@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_arm64_rel.def b/chromium/third_party/abseil-cpp/symbols_arm64_rel.def
index 2d3c6fca578..e0b68df13b5 100644
--- a/chromium/third_party/abseil-cpp/symbols_arm64_rel.def
+++ b/chromium/third_party/abseil-cpp/symbols_arm64_rel.def
@@ -3,6 +3,12 @@ EXPORTS
     ??$?0V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAA@$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?MUsecond_tag@detail@cctz@time_internal@absl@@U01234@@detail@cctz@time_internal@absl@@YA_NAEBV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@0@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAPEBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAPEBD@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -62,12 +68,18 @@ EXPORTS
     ??$GenericCompare@HVstring_view@absl@@@absl@@YAHAEBVCord@0@AEBVstring_view@0@_K@Z
     ??$GenericCompare@_NVCord@absl@@@absl@@YA_NAEBVCord@0@0_K@Z
     ??$GenericCompare@_NVstring_view@absl@@@absl@@YA_NAEBVCord@0@AEBVstring_view@0@_K@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
     ??$ParseFloat@$09@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFloat@$0BA@@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFormatString@UParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@@str_format_internal@absl@@YA_NVstring_view@1@UParsedFormatConsumer@ParsedFormatBase@01@@Z
     ??$Prepend@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@0@AEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@3@@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YAHAEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@2@@Z
     ??$__construct_node_hash@AEBUpiecewise_construct_t@__1@std@@V?$tuple@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$tuple@$$V@23@@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@AEAA?AV?$unique_ptr@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@@12@_KAEBUpiecewise_construct_t@12@$$QEAV?$tuple@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@12@$$QEAV?$tuple@$$V@12@@Z
@@ -91,7 +103,6 @@ EXPORTS
     ??0?$__split_buffer@UTransition@cctz@time_internal@absl@@AEAV?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransition@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UViableSubstitution@strings_internal@absl@@AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@12@@Z
-    ??0AlphaNum@absl@@QEAA@PEBD@Z
     ??0AlphaNum@absl@@QEAA@UDec@1@@Z
     ??0AlphaNum@absl@@QEAA@UHex@1@@Z
     ??0AlphaNum@absl@@QEAA@_K@Z
@@ -99,6 +110,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QEAA@PEBX@Z
     ??0Arg@substitute_internal@absl@@QEAA@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QEAA@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@$$QEAV01@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@AEBV01@@Z
     ??0BadStatusOrAccess@absl@@QEAA@VStatus@1@@Z
     ??0BlockingCounter@absl@@QEAA@H@Z
     ??0ByAnyChar@absl@@QEAA@Vstring_view@1@@Z
@@ -143,6 +156,8 @@ EXPORTS
     ??1bad_optional_access@absl@@UEAA@XZ
     ??1bad_variant_access@absl@@UEAA@XZ
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IEAAAEAV012@$$QEAV012@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@AEBV01@@Z
     ??4Cord@absl@@QEAAAEAV01@Vstring_view@1@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVCord@0@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVStatus@0@@Z
@@ -168,6 +183,7 @@ EXPORTS
     ??ACord@absl@@QEBAD_K@Z
     ??BCord@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ??Bint128@absl@@QEBANXZ
+    ??EChunkIterator@Cord@absl@@QEAAAEAV012@XZ
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Hdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
@@ -196,7 +212,7 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPEBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AEAA?AV23@_K@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AEAAX_K@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceStack@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPEAX_K@Z
@@ -204,6 +220,7 @@ EXPORTS
     ?AlreadyExistsError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Append@Cord@absl@@QEAAX$$QEAV12@@Z
     ?Append@Cord@absl@@QEAAXAEBV12@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QEAAXVstring_view@3@@Z
@@ -213,6 +230,7 @@ EXPORTS
     ?AppendLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
     ?AppendPack@str_format_internal@absl@@YAAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?AppendTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -269,20 +287,24 @@ EXPORTS
     ?CompareSlowPath@Cord@absl@@AEBAHAEBV12@_K1@Z
     ?CompareSlowPath@Cord@absl@@AEBAHVstring_view@2@_K1@Z
     ?ConcatNodes@CordForest@absl@@QEAAPEAUCordRep@cord_internal@2@XZ
+    ?Consume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPEBDPEBD0PEAUUnboundConversion@12@PEAH@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAC_K@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAW4ctrl_t@12@_K@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_NAEBUUnboundConversion@34@Vstring_view@4@@Z
     ?Copy@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@II_K@Z
     ?CopyCordToString@absl@@YAXAEBVCord@1@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
     ?CopyTo@InlineRep@Cord@absl@@QEBAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@AEBAXPEAD@Z
     ?Crash@Helper@internal_statusor@absl@@SAXAEBVStatus@3@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K11@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPEAUThreadIdentity@base_internal@2@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPEAUThreadIdentity@12@XZ
@@ -305,6 +327,8 @@ EXPORTS
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AEAAXXZ
     ?DestroyCordSlow@Cord@absl@@AEAAXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QEAA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QEBA_NPEBV123@@Z
@@ -317,6 +341,9 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPEBX_J@Z@base_internal@absl@@CAXPEBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PEBDHPEAPEADPEAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PEBDHPEAPEADPEAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPEAXQEBQEAXQEAHHH_NP6AXPEBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
@@ -410,8 +437,11 @@ EXPORTS
     ?FromTM@absl@@YA?AVTime@1@AEBUtm@@VTimeZone@1@@Z
     ?FromUDate@absl@@YA?AVTime@1@N@Z
     ?FromUniversal@absl@@YA?AVTime@1@_J@Z
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AEAA?AV?$Span@D@3@_K@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QEBAD_K@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QEBAD_K@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QEBA?AUCordzStatistics@23@XZ
     ?GetCurrentTimeNanos@absl@@YA_JXZ
@@ -450,7 +480,7 @@ EXPORTS
     ?IncrementSynchSem@Mutex@absl@@CAXPEAV12@PEAUPerThreadSynch@base_internal@2@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXAEBV123@@Z
-    ?InitTree@ChunkIterator@Cord@absl@@AEAAXPEAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@AEBAXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AEAAXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PEAUCordRepExternal@12@@Z
     ?InitializeSymbolizer@absl@@YAXPEBD@Z
@@ -466,7 +496,8 @@ EXPORTS
     ?IsDataLoss@absl@@YA_NAEBVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NAEBVStatus@1@@Z
     ?IsFailedPrecondition@absl@@YA_NAEBVStatus@1@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
     ?IsInternal@absl@@YA_NAEBVStatus@1@@Z
     ?IsInvalidArgument@absl@@YA_NAEBVStatus@1@@Z
     ?IsNotFound@absl@@YA_NAEBVStatus@1@@Z
@@ -478,6 +509,7 @@ EXPORTS
     ?IsUnavailable@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnknown@absl@@YA_NAEBVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPEBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QEBA_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?Iterate@HashtablezSampler@container_internal@absl@@QEAA_JAEBV?$function@$$A6AXAEBUHashtablezInfo@container_internal@absl@@@Z@__1@std@@@Z
     ?LengthModToString@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4LengthMod@12@@Z
@@ -504,6 +536,7 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAEAVInlineData@23@AEBV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CA_KPEBUCordRep@cord_internal@2@@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@0@Z
     ?MovedFromString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AEAAXHPEBI@Z
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@QEAAXI@Z
@@ -522,7 +555,6 @@ EXPORTS
     ?New@CordRepFlat@cord_internal@absl@@SAPEAU123@_K@Z
     ?New@CordRepRing@cord_internal@absl@@CAPEAV123@_K0@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QEBAPEAV123@AEBVCordzSnapshot@23@@Z
     ?NextTransition@TimeZone@absl@@QEBA_NVTime@2@PEAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
@@ -561,9 +593,11 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AEAAXXZ
     ?Prepend@Cord@absl@@QEAAXAEBV12@@Z
     ?Prepend@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -578,6 +612,8 @@ EXPORTS
     ?PutPaddedString@FormatSinkImpl@str_format_internal@absl@@QEAA_NVstring_view@3@HH_N@Z
     ?RawLog@raw_logging_internal@absl@@YAXW4LogSeverity@2@PEBDH1ZZ
     ?RawLoggingFullySupported@raw_logging_internal@absl@@YA_NXZ
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUReadResult@123@_K0@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K0AEAPEAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QEAAHAEBUParsedFloat@23@H@Z
@@ -612,10 +648,11 @@ EXPORTS
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AEAA_NAEBV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QEBA_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPEBD_K@Z
     ?SampleSlow@container_internal@absl@@YAPEAUHashtablezInfo@12@PEA_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
     ?SetCapacityForTesting@CordRepRing@cord_internal@absl@@QEAAX_K@Z
     ?SetCurrentThreadIdentity@base_internal@absl@@YAXPEAUThreadIdentity@12@P6AXPEAX@Z@Z
     ?SetDisposeCallback@HashtablezSampler@container_internal@absl@@QEAAP6AXAEBUHashtablezInfo@23@@ZP6AX0@Z@Z
@@ -631,7 +668,7 @@ EXPORTS
     ?SetToZero@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXXZ
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QEAAXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QEAAXXZ
     ?SignalAll@CondVar@absl@@QEAAXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PEA_N@Z
@@ -641,6 +678,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SA_KXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
     ?SlowLock@SpinLock@base_internal@absl@@AEAAXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AEAAXI@Z
     ?SnprintF@str_format_internal@absl@@YAHPEAD_KVUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -661,6 +699,7 @@ EXPORTS
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AEAAXI_K@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@_K11@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QEAAPEAUCordRep@23@_K0@Z
     ?Subcord@Cord@absl@@QEBA?AV12@_K0@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PEBV62@_K@Z
     ?Summarize@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -785,8 +824,11 @@ EXPORTS
     ?__swap_out_circular_buffer@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@AEAAPEAUTransition@cctz@time_internal@absl@@AEAU?$__split_buffer@UTransition@cctz@time_internal@absl@@AEAV?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@23@PEAU4567@@Z
     ?__swap_out_circular_buffer@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@AEAAPEAUTransitionType@cctz@time_internal@absl@@AEAU?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@23@PEAU4567@@Z
     ?__vallocate@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@AEAAX_K@Z
+    ?chunk_begin@Cord@absl@@QEBA?AVChunkIterator@12@XZ
     ?clear@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAXXZ
     ?code@Status@absl@@QEBA?AW4StatusCode@2@XZ
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_exhaustive_validation@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?day_difference@impl@detail@cctz@time_internal@absl@@YA_J_JCC0CC@Z
     ?description@time_zone@cctz@time_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_x64_dbg.def b/chromium/third_party/abseil-cpp/symbols_x64_dbg.def
index a72bdc36ed2..fa8d8f08532 100644
--- a/chromium/third_party/abseil-cpp/symbols_x64_dbg.def
+++ b/chromium/third_party/abseil-cpp/symbols_x64_dbg.def
@@ -1,6 +1,7 @@
 EXPORTS
     ??$?0$$CBD$0A@@VoidPtr@str_format_internal@absl@@QEAA@PEBD@Z
     ??$?0$$CBU?$atomic@_N@__1@std@@@Condition@absl@@QEAA@P6A_NPEBU?$atomic@_N@__1@std@@@Z0@Z
+    ??$?0$$CBUCordRep@cord_internal@absl@@@Hex@absl@@QEAA@PEBUCordRep@cord_internal@1@W4PadSpec@1@@Z
     ??$?0$$CBVFormatArgImpl@str_format_internal@absl@@$$CBV012@@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@V?$initializer_list@VFormatArgImpl@str_format_internal@absl@@@std@@@Z
     ??$?0$$T@?$Storage@PEAH$00$0A@@internal_compressed_tuple@container_internal@absl@@QEAA@Uin_place_t@3@$$QEA$$T@Z
     ??$?0$$T@?$Storage@PEAPEAUCordRep@cord_internal@absl@@$00$0A@@internal_compressed_tuple@container_internal@absl@@QEAA@Uin_place_t@3@$$QEA$$T@Z
@@ -52,7 +53,6 @@ EXPORTS
     ??$?0AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@X@?$__compressed_pair_elem@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@$0A@$0A@@__1@std@@QEAA@AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@Z
     ??$?0AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@12@@?$__compressed_pair@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@@__1@std@@QEAA@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@12@$$QEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@12@@Z
     ??$?0AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@X@?$__compressed_pair_elem@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@$0A@$0A@@__1@std@@QEAA@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@12@@Z
-    ??$?0AEAPEAUCordRep@cord_internal@absl@@AEAPEAU012@$0A@@?$pair@PEAUCordRep@cord_internal@absl@@PEAU123@@__1@std@@QEAA@AEAPEAUCordRep@cord_internal@absl@@0@Z
     ??$?0AEAPEAUThreadIdentity@base_internal@absl@@AEBQ6AXPEAX@Z@?$__compressed_pair@PEAUThreadIdentity@base_internal@absl@@P6AXPEAX@Z@__1@std@@QEAA@AEAPEAUThreadIdentity@base_internal@absl@@AEBQ6AXPEAX@Z@Z
     ??$?0AEAPEAUThreadIdentity@base_internal@absl@@X@?$__compressed_pair_elem@PEAUThreadIdentity@base_internal@absl@@$0A@$0A@@__1@std@@QEAA@AEAPEAUThreadIdentity@base_internal@absl@@@Z
     ??$?0AEAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U__default_init_tag@__1@std@@@?$__compressed_pair@PEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAA@AEAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$QEAU__default_init_tag@12@@Z
@@ -221,7 +221,19 @@ EXPORTS
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAPEBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAPEBD@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAH$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
-    ??$?XH@Duration@absl@@QEAAAEAV01@H@Z
+    ??$?XH$0A@@Duration@absl@@QEAAAEAV01@H@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AEAAXPEAUCordRep@12@@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AEAAXV?$Span@QEAUCordRep@cord_internal@absl@@@2@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AEAAXPEAUCordRep@12@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AEAAXV?$Span@QEAUCordRep@cord_internal@absl@@@2@@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$AddEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -350,6 +362,8 @@ EXPORTS
     ??$HidePtr@$$CBX@base_internal@absl@@YA_KPEBX@Z
     ??$HidePtr@U?$atomic@_J@__1@std@@@base_internal@absl@@YA_KPEAU?$atomic@_J@__1@std@@@Z
     ??$HidePtr@X@base_internal@absl@@YA_KPEAX@Z
+    ??$Hours@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Init@$0A@@CordRepBtreeNavigator@cord_internal@absl@@AEAAPEAUCordRep@12@PEAVCordRepBtree@12@@Z
     ??$Init@H@FormatArgImpl@str_format_internal@absl@@AEAAXAEBH@Z
     ??$Initialize@V?$CopyValueAdapter@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@@?$Storage@PEAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXV?$CopyValueAdapter@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@12@_K@Z
     ??$Invoke@A6AXXZ$$V@Callable@base_internal@absl@@SAXA6AXXZ@Z
@@ -365,7 +379,19 @@ EXPORTS
     ??$MakeSpan@$SI$0CIA@@absl@@YA?AV?$Span@I@0@AEAY0CIA@I@Z
     ??$MakeSpan@$SI$0IA@@absl@@YA?AV?$Span@I@0@AEAY0IA@I@Z
     ??$MakeSpan@$SVFormatArgImpl@str_format_internal@absl@@@absl@@YA?AV?$Span@VFormatArgImpl@str_format_internal@absl@@@0@PEAVFormatArgImpl@str_format_internal@0@_K@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Microseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Microseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Milliseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Milliseconds@K$0A@@absl@@YA?AVDuration@0@K@Z
     ??$Milliseconds@N$0A@@absl@@YA?AVDuration@0@N@Z
+    ??$Minutes@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Nanoseconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QEBA_KXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00@absl@@U?$integer_sequence@_K$0A@$00$01@5@@internal_layout@container_internal@absl@@QEBA_KXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@@absl@@U?$integer_sequence@_K$0A@$00@5@@internal_layout@container_internal@absl@@QEBA_KXZ
@@ -395,6 +421,11 @@ EXPORTS
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitialized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
+    ??$Seconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Seconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Seconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$SharedCompareImpl@VCord@absl@@@absl@@YAHAEBVCord@0@0@Z
     ??$SharedCompareImpl@Vstring_view@absl@@@absl@@YAHAEBVCord@0@AEBVstring_view@0@@Z
     ??$StrAppend@$$V@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@0@1111@Z
@@ -643,7 +674,6 @@ EXPORTS
     ??$forward@AEAPEAPEBUCordRep@cord_internal@absl@@@__1@std@@YAAEAPEAPEBUCordRep@cord_internal@absl@@AEAPEAPEBU234@@Z
     ??$forward@AEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@YAAEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEAPEAPEBV23456@@Z
     ??$forward@AEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@YAAEAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@01@AEAPEAU201@@Z
-    ??$forward@AEAPEAUCordRep@cord_internal@absl@@@__1@std@@YAAEAPEAUCordRep@cord_internal@absl@@AEAPEAU234@@Z
     ??$forward@AEAPEAUPayload@status_internal@absl@@@__1@std@@YAAEAPEAUPayload@status_internal@absl@@AEAPEAU234@@Z
     ??$forward@AEAPEAUSubRange@absl@@@__1@std@@YAAEAPEAUSubRange@absl@@AEAPEAU23@@Z
     ??$forward@AEAPEAUThreadIdentity@base_internal@absl@@@__1@std@@YAAEAPEAUThreadIdentity@base_internal@absl@@AEAPEAU234@@Z
@@ -745,7 +775,6 @@ EXPORTS
     ??$get@Vstring_view@absl@@V12@@?$__get_pair@$0A@@__1@std@@SAAEBVstring_view@absl@@AEBU?$pair@Vstring_view@absl@@V12@@12@@Z
     ??$invoke@A6AXXZ$$V@base_internal@absl@@YAXA6AXXZ@Z
     ??$lower_bound@PEBUTransition@cctz@time_internal@absl@@U1234@UByUnixTime@1234@@__1@std@@YAPEBUTransition@cctz@time_internal@absl@@PEBU2345@0AEBU2345@UByUnixTime@2345@@Z
-    ??$make_pair@AEAPEAUCordRep@cord_internal@absl@@AEAPEAU123@@__1@std@@YA?AU?$pair@PEAUCordRep@cord_internal@absl@@PEAU123@@01@AEAPEAUCordRep@cord_internal@absl@@0@Z
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$V@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@XZ
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@AEAV12@@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@Z
     ??$max_size@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@X@?$allocator_traits@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@SA_KAEBV?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@12@@Z
@@ -782,6 +811,7 @@ EXPORTS
     ??$move@AEAUTransition@cctz@time_internal@absl@@@__1@std@@YA$$QEAUTransition@cctz@time_internal@absl@@AEAU2345@@Z
     ??$move@AEAUTransitionType@cctz@time_internal@absl@@@__1@std@@YA$$QEAUTransitionType@cctz@time_internal@absl@@AEAU2345@@Z
     ??$move@AEAUViableSubstitution@strings_internal@absl@@@__1@std@@YA$$QEAUViableSubstitution@strings_internal@absl@@AEAU234@@Z
+    ??$move@AEAV?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@@__1@std@@YA$$QEAV?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@AEAV23@@Z
     ??$move@AEAV?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@01@AEAV201@@Z
     ??$move@AEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@01@AEAV201@@Z
     ??$move@AEAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QEAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AEAV201@@Z
@@ -843,7 +873,9 @@ EXPORTS
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@PEBVFormatArgImpl@str_format_internal@1@_K@Z
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@XZ
     ??0?$Span@D@absl@@QEAA@PEAD_K@Z
+    ??0?$Span@D@absl@@QEAA@XZ
     ??0?$Span@I@absl@@QEAA@PEAI_K@Z
+    ??0?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEAA@PEBQEAUCordRep@cord_internal@1@_K@Z
     ??0?$Span@QEAX@absl@@QEAA@PEBQEAX_K@Z
     ??0?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEAA@PEAVFormatArgImpl@str_format_internal@1@_K@Z
     ??0?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAA@XZ
@@ -994,6 +1026,7 @@ EXPORTS
     ??0?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
     ??0?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
     ??0?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEAA@XZ
+    ??0AlphaNum@absl@@QEAA@H@Z
     ??0AlphaNum@absl@@QEAA@PEBD@Z
     ??0AlphaNum@absl@@QEAA@UDec@1@@Z
     ??0AlphaNum@absl@@QEAA@UHex@1@@Z
@@ -1004,6 +1037,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QEAA@PEBX@Z
     ??0Arg@substitute_internal@absl@@QEAA@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QEAA@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@$$QEAV01@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@AEBV01@@Z
     ??0BadStatusOrAccess@absl@@QEAA@VStatus@1@@Z
     ??0BlockingCounter@absl@@QEAA@H@Z
     ??0BoundConversion@str_format_internal@absl@@QEAA@XZ
@@ -1026,11 +1061,13 @@ EXPORTS
     ??0Cord@absl@@QEAA@XZ
     ??0CordForest@absl@@QEAA@_K@Z
     ??0CordRep@cord_internal@absl@@QEAA@XZ
+    ??0CordRepBtree@cord_internal@absl@@AEAA@XZ
+    ??0CordRepBtreeNavigator@cord_internal@absl@@QEAA@XZ
+    ??0CordRepBtreeReader@cord_internal@absl@@QEAA@XZ
     ??0CordRepConcat@cord_internal@absl@@QEAA@XZ
     ??0CordRepExternal@cord_internal@absl@@QEAA@XZ
     ??0CordRepFlat@cord_internal@absl@@QEAA@XZ
     ??0CordRepRing@cord_internal@absl@@AEAA@I@Z
-    ??0CordRepRingReader@cord_internal@absl@@QEAA@XZ
     ??0CordRepSubstring@cord_internal@absl@@QEAA@XZ
     ??0CordzHandle@cord_internal@absl@@IEAA@_N@Z
     ??0CordzHandle@cord_internal@absl@@QEAA@XZ
@@ -1047,9 +1084,10 @@ EXPORTS
     ??0FormatConversionSpecImpl@str_format_internal@absl@@QEAA@XZ
     ??0FormatSinkImpl@str_format_internal@absl@@QEAA@VFormatRawSinkImpl@12@@Z
     ??0GraphCycles@synchronization_internal@absl@@QEAA@XZ
-    ??0GroupSse2Impl@container_internal@absl@@QEAA@PEBC@Z
+    ??0GroupSse2Impl@container_internal@absl@@QEAA@PEBW4ctrl_t@12@@Z
     ??0HashtablezInfo@container_internal@absl@@QEAA@XZ
     ??0HashtablezSampler@container_internal@absl@@QEAA@XZ
+    ??0Hex@absl@@AEAA@W4PadSpec@1@_K@Z
     ??0Impl@time_zone@cctz@time_internal@absl@@AEAA@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??0InlineData@cord_internal@absl@@QEAA@W4DefaultInitType@012@@Z
     ??0InlineData@cord_internal@absl@@QEAA@XZ
@@ -1078,6 +1116,7 @@ EXPORTS
     ??0SpinLock@base_internal@absl@@QEAA@W4SchedulingMode@12@@Z
     ??0SpinLockHolder@base_internal@absl@@QEAA@PEAVSpinLock@12@@Z
     ??0Status@absl@@QEAA@$$QEAV01@@Z
+    ??0Status@absl@@QEAA@AEBV01@@Z
     ??0Status@absl@@QEAA@W4StatusCode@1@Vstring_view@1@@Z
     ??0StatusRep@status_internal@absl@@QEAA@W4StatusCode@2@Vstring_view@2@V?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@Z
     ??0Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEAA@_KAEBV?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@Z
@@ -1120,6 +1159,8 @@ EXPORTS
     ??0int128@absl@@QEAA@M@Z
     ??0int128@absl@@QEAA@N@Z
     ??0int128@absl@@QEAA@O@Z
+    ??0once_flag@absl@@QEAA@XZ
+    ??0string_view@absl@@AEAA@PEBD_KUSkipCheckLengthTag@01@@Z
     ??0string_view@absl@@QEAA@PEBD@Z
     ??0string_view@absl@@QEAA@PEBD_K@Z
     ??0string_view@absl@@QEAA@XZ
@@ -1243,12 +1284,15 @@ EXPORTS
     ??4?$optional@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@absl@@QEAAAEAV01@$$QEAV01@@Z
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IEAAAEAV012@$$QEAV012@@Z
     ??4?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAAAEAV012@$$QEAV012@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@AEBV01@@Z
     ??4Cord@absl@@QEAAAEAV01@$$QEAV01@@Z
     ??4Cord@absl@@QEAAAEAV01@Vstring_view@1@@Z
     ??4CordzUpdateTracker@cord_internal@absl@@QEAAAEAV012@AEBV012@@Z
     ??4InlineRep@Cord@absl@@QEAAAEAV012@$$QEAV012@@Z
     ??4Payload@status_internal@absl@@QEAAAEAU012@$$QEAU012@@Z
     ??4Status@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4Status@absl@@QEAAAEAV01@AEBV01@@Z
     ??4int128@absl@@QEAAAEAV01@H@Z
     ??4uint128@absl@@QEAAAEAV01@H@Z
     ??4uint128@absl@@QEAAAEAV01@_J@Z
@@ -1305,6 +1349,7 @@ EXPORTS
     ??A?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAAEBUPayload@status_internal@1@_K@Z
     ??A?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAAEBVFormatArgImpl@str_format_internal@1@_K@Z
     ??A?$Span@I@absl@@QEBAAEAI_K@Z
+    ??A?$array@PEAUCordRep@cord_internal@absl@@$01@__1@std@@QEAAAEAPEAUCordRep@cord_internal@absl@@_K@Z
     ??A?$unique_ptr@$$BY0A@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@V?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@23@@__1@std@@QEBAAEAPEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@12@_K@Z
     ??A?$unordered_map@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAAEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@12@@Z
     ??A?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransition@cctz@time_internal@absl@@_K@Z
@@ -1319,7 +1364,7 @@ EXPORTS
     ??B?$unique_ptr@VTimeZoneIf@cctz@time_internal@absl@@U?$default_delete@VTimeZoneIf@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_NXZ
     ??B?$unique_ptr@VZoneInfoSource@cctz@time_internal@absl@@U?$default_delete@VZoneInfoSource@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_NXZ
     ??BCord@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ??BCordRepRingReader@cord_internal@absl@@QEBA_NXZ
+    ??BCordRepBtreeReader@cord_internal@absl@@QEBA_NXZ
     ??BTimeZone@absl@@QEBA?AVtime_zone@cctz@time_internal@1@XZ
     ??Bint128@absl@@QEBAEXZ
     ??Bint128@absl@@QEBANXZ
@@ -1443,6 +1488,7 @@ EXPORTS
     ??R<lambda_2>@?0???$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@0_K1@Z@QEBA?A?<auto>@@I@Z
     ??R<lambda_2>@?0???$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@0_K1@Z@QEBA?A?<auto>@@I@Z
     ??R<lambda_2>@?0??erase@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEAAPEAUPayload@status_internal@3@PEBU453@@Z@QEBA?A?<auto>@@XZ
+    ??R?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@absl@@QEBAXPEAUCordRep@cord_internal@1@_K1@Z
     ??R?$FunctionRef@$$A6AXV?$Span@I@absl@@@Z@absl@@QEBAXV?$Span@I@1@@Z
     ??R?$FunctionRef@$$A6AXVstring_view@absl@@@Z@absl@@QEBAXVstring_view@1@@Z
     ??R?$__allocator_destructor@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAXPEAPEBVImpl@time_zone@cctz@time_internal@absl@@@Z
@@ -1468,6 +1514,7 @@ EXPORTS
     ??RByUnixTime@Transition@cctz@time_internal@absl@@QEBA_NAEBU1234@0@Z
     ??Sabsl@@YA?AVuint128@0@V10@@Z
     ??Tabsl@@YA?AVuint128@0@V10@0@Z
+    ??Uabsl@@YA?AVuint128@0@V10@0@Z
     ??Ustr_format_internal@absl@@YA?AW4Flags@01@W4201@0@Z
     ??XDuration@absl@@QEAAAEAV01@N@Z
     ??XDuration@absl@@QEAAAEAV01@_J@Z
@@ -1520,12 +1567,14 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPEBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AEAA?AV23@_K@Z
+    ?AdvanceBtree@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?AdvanceBytes@ChunkIterator@Cord@absl@@AEAAX_K@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AEAAX_K@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AEAAX_K@Z
-    ?AdvanceRing@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?AdvanceStack@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?Align@adl_barrier@internal_layout@container_internal@absl@@YA_K_K0@Z
+    ?AlignBegin@CordRepBtree@cord_internal@absl@@AEAAXXZ
+    ?AlignEnd@CordRepBtree@cord_internal@absl@@AEAAXXZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPEAX_K@Z
     ?AllocSize@?$LayoutImpl@V?$tuple@_KPEAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@_K$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QEBA_KXZ
     ?AllocSize@CordRepRing@cord_internal@absl@@SA_K_K@Z
@@ -1544,6 +1593,8 @@ EXPORTS
     ?Append@Cord@absl@@QEAAX$$QEAV12@@Z
     ?Append@Cord@absl@@QEAAXAEBV12@@Z
     ?Append@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QEAAXVstring_view@3@@Z
@@ -1554,6 +1605,7 @@ EXPORTS
     ?AppendNode@CordForest@absl@@AEAAPEAUCordRep@cord_internal@2@PEAU342@0@Z
     ?AppendPack@str_format_internal@absl@@YAAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendText@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_KVstring_view@4@@Z
     ?AppendTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -1567,6 +1619,8 @@ EXPORTS
     ?AssertHeld@Mutex@absl@@QEBAXXZ
     ?AssertNotHeld@Mutex@absl@@QEBAXXZ
     ?AssertReaderHeld@Mutex@absl@@QEBAXXZ
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@_N@Z
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPEBV123@PEBV123@_N@Z
     ?AssignLargeString@Cord@absl@@AEAAAEAV12@$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?AssignNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PEAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAUPayload@status_internal@3@@Z
     ?AssignSlow@InlineRep@Cord@absl@@AEAAXAEBV123@@Z
@@ -1631,28 +1685,39 @@ EXPORTS
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@PEBUPayload@status_internal@absl@@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PEAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PEAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PEAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@USubRange@absl@@@__1@std@@V?$move_iterator@PEAUSubRange@absl@@@23@@inlined_vector_internal@absl@@QEAAXPEAV?$allocator@USubRange@absl@@@__1@std@@PEAUSubRange@3@@Z
+    ?Consume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?ConsumePrefix@absl@@YA_NPEAVstring_view@1@V21@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPEBDPEBD0PEAUUnboundConversion@12@PEAH@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@D@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@W4FormatConversionChar@2@@Z
     ?ControlWord@base_internal@absl@@YAPEAU?$atomic@I@__1@std@@PEAVonce_flag@2@@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAC_K@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAW4ctrl_t@12@_K@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_NAEBUUnboundConversion@34@Vstring_view@4@@Z
-    ?ConvertSpecialToEmptyAndFullToDeleted@GroupSse2Impl@container_internal@absl@@QEBAXPEAC@Z
+    ?ConvertSpecialToEmptyAndFullToDeleted@GroupSse2Impl@container_internal@absl@@QEBAXPEAW4ctrl_t@23@@Z
+    ?Copy@CordRepBtree@cord_internal@absl@@AEBAPEAV123@XZ
     ?Copy@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@II_K@Z
+    ?CopyBeginTo@CordRepBtree@cord_internal@absl@@AEBAPEAV123@_K0@Z
     ?CopyCordToString@absl@@YAXAEBVCord@1@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
+    ?CopyRaw@CordRepBtree@cord_internal@absl@@AEBAPEAV123@XZ
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
     ?CopyTo@InlineRep@Cord@absl@@QEBAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@AEBAXPEAD@Z
+    ?CopyToEndFrom@CordRepBtree@cord_internal@absl@@AEBAPEAV123@_K0@Z
     ?Crash@Helper@internal_statusor@absl@@SAXAEBVStatus@3@@Z
+    ?Create@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K11@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPEAUThreadIdentity@base_internal@2@XZ
+    ?Current@CordRepBtreeNavigator@cord_internal@absl@@QEBAPEAUCordRep@23@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPEAUThreadIdentity@12@XZ
+    ?Data@CordRepBtree@cord_internal@absl@@QEBA?AVstring_view@3@_K@Z
     ?Data@CordRepFlat@cord_internal@absl@@QEAAPEADXZ
     ?Data@CordRepFlat@cord_internal@absl@@QEBAPEBDXZ
     ?DataLength@Header@TimeZoneInfo@cctz@time_internal@absl@@QEBA_K_K@Z
@@ -1671,6 +1736,7 @@ EXPORTS
     ?DecrementSynchSem@Mutex@absl@@CA_NPEAV12@PEAUPerThreadSynch@base_internal@2@VKernelTimeout@synchronization_internal@2@@Z
     ?DefaultArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@XZ
     ?DefaultStackUnwinder@absl@@YAHPEAPEAXPEAHHHPEBX1@Z
+    ?Delete@CordRepBtree@cord_internal@absl@@CAXPEAV123@@Z
     ?Delete@CordRepExternal@cord_internal@absl@@SAXPEAUCordRep@23@@Z
     ?Delete@CordRepFlat@cord_internal@absl@@SAXPEAUCordRep@23@@Z
     ?Delete@CordRepRing@cord_internal@absl@@CAXPEAV123@@Z
@@ -1681,10 +1747,14 @@ EXPORTS
     ?Description@TimeZoneInfo@cctz@time_internal@absl@@UEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Description@TimeZoneLibC@cctz@time_internal@absl@@UEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Destroy@CordRep@cord_internal@absl@@SAXPEAU123@@Z
+    ?Destroy@CordRepBtree@cord_internal@absl@@SAXPEAV123@@Z
     ?Destroy@CordRepRing@cord_internal@absl@@CAXPEAV123@@Z
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AEAAXXZ
     ?DestroyCordSlow@Cord@absl@@AEAAXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyTree@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QEAA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QEBA_NPEBV123@@Z
@@ -1723,9 +1793,18 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPEBX_J@Z@base_internal@absl@@CAXPEBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PEBDHPEAPEADPEAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PEBDHPEAPEADPEAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPEAXQEBQEAXQEAHHH_NP6AXPEBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QEBAPEAUCordRep@23@W4EdgeType@123@@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QEBAPEAUCordRep@23@_K@Z
+    ?EdgeData@CordRepBtree@cord_internal@absl@@SA?AVstring_view@3@PEBUCordRep@23@@Z
+    ?EdgeDataPtr@CordRepBtree@cord_internal@absl@@SAPEBDPEBUCordRep@23@@Z
+    ?Edges@CordRepBtree@cord_internal@absl@@QEBA?AV?$Span@QEAUCordRep@cord_internal@absl@@@3@XZ
+    ?Edges@CordRepBtree@cord_internal@absl@@QEBA?AV?$Span@QEAUCordRep@cord_internal@absl@@@3@_K0@Z
     ?EmplaceTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@AEBVInlineData@53@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmplaceTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmptyString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
@@ -1763,7 +1842,6 @@ EXPORTS
     ?Find@ByChar@absl@@QEBA?AVstring_view@2@V32@_K@Z
     ?Find@ByLength@absl@@QEBA?AVstring_view@2@V32@_K@Z
     ?Find@ByString@absl@@QEBA?AVstring_view@2@V32@_K@Z
-    ?Find@CordRepRing@cord_internal@absl@@QEBA?AUPosition@123@I_K@Z
     ?Find@CordRepRing@cord_internal@absl@@QEBA?AUPosition@123@_K@Z
     ?FindFlatStartPiece@InlineRep@Cord@absl@@QEBA?AVstring_view@3@XZ
     ?FindPath@GraphCycles@synchronization_internal@absl@@QEBAHUGraphId@23@0HQEAU423@@Z
@@ -1866,13 +1944,16 @@ EXPORTS
     ?GetAllocator@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@UPayload@status_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEAV?$allocator@USubRange@absl@@@__1@std@@XZ
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AEAA?AV?$Span@D@3@_K@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAAEA_KXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QEBAD_K@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QEBAD_K@Z
     ?GetCond@WinHelper@Waiter@synchronization_internal@absl@@SAPEAU_RTL_CONDITION_VARIABLE@@PEAV234@@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QEBA?AUCordzStatistics@23@XZ
@@ -1956,28 +2037,34 @@ EXPORTS
     ?GetYearDay@absl@@YAHV?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@1@@Z
     ?Global@HashtablezSampler@container_internal@absl@@SAAEAV123@XZ
     ?GuaranteedEqual@Condition@absl@@SA_NPEBV12@0@Z
-    ?H1@container_internal@absl@@YA_K_KPEBC@Z
+    ?H1@container_internal@absl@@YA_K_KPEBW4ctrl_t@12@@Z
     ?HandleInvalidStatusCtorArg@Helper@internal_statusor@absl@@SAXPEAVStatus@3@@Z
     ?HasBeenNotifiedInternal@Notification@absl@@CA_NPEBU?$atomic@_N@__1@std@@@Z
     ?HasEdge@GraphCycles@synchronization_internal@absl@@QEBA_NUGraphId@23@0@Z
     ?HasNode@GraphCycles@synchronization_internal@absl@@QEAA_NUGraphId@23@@Z
-    ?HashSeed@container_internal@absl@@YA_KPEBC@Z
+    ?HashSeed@container_internal@absl@@YA_KPEBW4ctrl_t@12@@Z
     ?Head@CordzInfo@cord_internal@absl@@SAPEAV123@AEBVCordzSnapshot@23@@Z
     ?HexStringToBytes@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@@Z
     ?HideMask@base_internal@absl@@YA_KXZ
-    ?Hours@absl@@YA?AVDuration@1@_J@Z
     ?IDivDuration@absl@@YA_JVDuration@1@0PEAV21@@Z
     ?IDivDuration@time_internal@absl@@YA_J_NVDuration@2@1PEAV32@@Z
     ?In@Time@absl@@QEBA?AUBreakdown@12@VTimeZone@2@@Z
     ?InMillisecondsFromNow@KernelTimeout@synchronization_internal@absl@@AEBAKXZ
     ?Increment@Refcount@cord_internal@absl@@QEAAXXZ
     ?IncrementSynchSem@Mutex@absl@@CAXPEAV12@PEAUPerThreadSynch@base_internal@2@@Z
+    ?IndexBefore@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@U4123@_K@Z
+    ?IndexBeyond@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@_K@Z
+    ?IndexOf@CordRepBtree@cord_internal@absl@@AEBA?AUPosition@123@_K@Z
     ?InfiniteDuration@absl@@YA?AVDuration@1@XZ
     ?InfiniteFuture@absl@@YA?AVTime@1@XZ
     ?InfinitePast@absl@@YA?AVTime@1@XZ
+    ?Init@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@PEAVCordRepBtree@23@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
+    ?InitFirst@CordRepBtreeNavigator@cord_internal@absl@@QEAAPEAUCordRep@23@PEAVCordRepBtree@23@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXAEBV123@@Z
+    ?InitInstance@CordRepBtree@cord_internal@absl@@AEAAXH_K0@Z
     ?InitTree@ChunkIterator@Cord@absl@@AEAAXPEAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@AEBAXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AEAAXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PEAUCordRepExternal@12@@Z
     ?InitializeData@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@AEAAPEAPEAUCordRep@cord_internal@3@XZ
@@ -1996,14 +2083,19 @@ EXPORTS
     ?InvalidGraphId@synchronization_internal@absl@@YA?AUGraphId@12@XZ
     ?IsAborted@absl@@YA_NAEBVStatus@1@@Z
     ?IsAlreadyExists@absl@@YA_NAEBVStatus@1@@Z
+    ?IsBtree@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsCancelled@absl@@YA_NAEBVStatus@1@@Z
+    ?IsConcat@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsCooperative@SpinLock@base_internal@absl@@CA_NW4SchedulingMode@23@@Z
+    ?IsDataEdge@CordRepBtree@cord_internal@absl@@SA_NPEBUCordRep@23@@Z
     ?IsDataLoss@absl@@YA_NAEBVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NAEBVStatus@1@@Z
     ?IsEmpty@Queue@CordzHandle@cord_internal@absl@@QEBA_NXZ
+    ?IsExternal@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsFailedPrecondition@absl@@YA_NAEBVStatus@1@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
+    ?IsFlat@CordRep@cord_internal@absl@@QEBA_NXZ
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
     ?IsImmortal@Refcount@cord_internal@absl@@QEBA_NXZ
     ?IsInfiniteDuration@time_internal@absl@@YA_NVDuration@2@@Z
     ?IsInlined@Status@absl@@CA_N_K@Z
@@ -2016,11 +2108,14 @@ EXPORTS
     ?IsPermissionDenied@absl@@YA_NAEBVStatus@1@@Z
     ?IsReachable@GraphCycles@synchronization_internal@absl@@QEBA_NUGraphId@23@0@Z
     ?IsResourceExhausted@absl@@YA_NAEBVStatus@1@@Z
+    ?IsRing@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsSame@InlineRep@Cord@absl@@QEBA_NAEBV123@@Z
+    ?IsSubstring@CordRep@cord_internal@absl@@QEBA_NXZ
     ?IsUnauthenticated@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnavailable@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnknown@absl@@YA_NAEBVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPEBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QEBA_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?IsValidCapacity@container_internal@absl@@YA_N_K@Z
     ?IsValidIndex@CordRepRing@cord_internal@absl@@AEBA_NI@Z
@@ -2072,10 +2167,8 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAEAVInlineData@23@AEBV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CA_KPEBUCordRep@cord_internal@2@@Z
-    ?Microseconds@absl@@YA?AVDuration@1@_J@Z
-    ?Milliseconds@absl@@YA?AVDuration@1@_J@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@0@Z
     ?Min@string_view@absl@@CA_K_K0@Z
-    ?Minutes@absl@@YA?AVDuration@1@_J@Z
     ?MovedFromRep@Status@absl@@CA_KXZ
     ?MovedFromString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AEAAXHPEBI@Z
@@ -2093,13 +2186,16 @@ EXPORTS
     ?Mutable@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@_K@Z
     ?MutexDelay@synchronization_internal@absl@@YAHHH@Z
     ?Name@Impl@time_zone@cctz@time_internal@absl@@QEBAAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ?Nanoseconds@absl@@YA?AVDuration@1@_J@Z
     ?NegateAndSubtractOne@time_internal@absl@@YA_J_J@Z
     ?Never@KernelTimeout@synchronization_internal@absl@@SA?AV123@XZ
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@H@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@0@Z
     ?New@CordRepFlat@cord_internal@absl@@SAPEAU123@_K@Z
     ?New@CordRepRing@cord_internal@absl@@CAPEAV123@_K0@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
+    ?Next@CordRepBtreeNavigator@cord_internal@absl@@QEAAPEAUCordRep@23@XZ
+    ?Next@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QEBAPEAV123@AEBVCordzSnapshot@23@@Z
     ?NextCapacity@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@SA_K_K@Z
     ?NextCapacity@?$Storage@PEAUCordRep@cord_internal@absl@@$01V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@SA_K_K@Z
@@ -2112,6 +2208,7 @@ EXPORTS
     ?NextTransition@TimeZone@absl@@QEBA_NVTime@2@PEAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
     ?NextTransition@TimeZoneLibC@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
+    ?NextUp@CordRepBtreeNavigator@cord_internal@absl@@AEAAPEAUCordRep@23@XZ
     ?NominalCPUFrequency@base_internal@absl@@YANXZ
     ?NormalizeLogSeverity@absl@@YA?AW4LogSeverity@1@W421@@Z
     ?NotFoundError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
@@ -2121,6 +2218,7 @@ EXPORTS
     ?Now@UnscaledCycleClockWrapperForGetCurrentTime@time_internal@absl@@SA_JXZ
     ?Now@absl@@YA?AVTime@1@XZ
     ?NumCPUs@base_internal@absl@@YAHXZ
+    ?NumClonedBytes@container_internal@absl@@YA_KXZ
     ?ODRCheck@CordzHandle@cord_internal@absl@@AEBAXXZ
     ?ODRCheck@CordzInfo@cord_internal@absl@@AEBAXXZ
     ?OccursBefore@ViableSubstitution@strings_internal@absl@@QEBA_NAEBU123@@Z
@@ -2156,10 +2254,13 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AEAAXXZ
     ?Prepend@Cord@absl@@QEAAXAEBV12@@Z
     ?Prepend@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
     ?PrependNode@CordForest@absl@@AEAAPEAUCordRep@cord_internal@2@PEAU342@0@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -2180,6 +2281,8 @@ EXPORTS
     ?Read1To3@MixingHashState@hash_internal@absl@@CAIPEBE_K@Z
     ?Read4To8@MixingHashState@hash_internal@absl@@CA_KPEBE_K@Z
     ?Read9To16@MixingHashState@hash_internal@absl@@CA?AU?$pair@_K_K@__1@std@@PEBE_K@Z
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUReadResult@123@_K0@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K0AEAPEAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QEAAHAEBUParsedFloat@23@H@Z
@@ -2193,6 +2296,7 @@ EXPORTS
     ?ReclaimThreadIdentity@synchronization_internal@absl@@YAXPEAX@Z
     ?RecordInsertSlow@container_internal@absl@@YAXPEAUHashtablezInfo@12@_K1@Z
     ?Ref@CordRep@cord_internal@absl@@SAPEAU123@PEAU123@@Z
+    ?Ref@Status@absl@@CAX_K@Z
     ?RefCordRep@CordzInfo@cord_internal@absl@@QEBAPEAUCordRep@23@XZ
     ?Register@CycleClockSource@base_internal@absl@@CAXP6A_JXZ@Z
     ?Register@HashtablezSampler@container_internal@absl@@QEAAPEAUHashtablezInfo@23@XZ
@@ -2220,19 +2324,19 @@ EXPORTS
     ?Reset@?$AllocationTransaction@V?$allocator@PEBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXXZ
-    ?Reset@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@PEAVCordRepRing@23@@Z
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AEAA_NAEBV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResetToEmpty@InlineRep@Cord@absl@@AEAAXXZ
     ?Resize@?$ResizeUninitializedTraits@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@SAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?RoundUp@cord_internal@absl@@YA_K_K0@Z
     ?RoundUpForTag@cord_internal@absl@@YA_K_K@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QEBA_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPEBD_K@Z
     ?SampleSlow@container_internal@absl@@YAPEAUHashtablezInfo@12@PEA_J@Z
-    ?Seconds@absl@@YA?AVDuration@1@_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
+    ?Seek@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
     ?SetAllocatedData@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAH_K@Z
     ?SetAllocatedData@?$Storage@PEAUCordRep@cord_internal@absl@@$01V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAPEAUCordRep@cord_internal@3@_K@Z
     ?SetAllocatedData@?$Storage@PEAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXPEAPEAUCordRep@cord_internal@3@_K@Z
@@ -2269,7 +2373,7 @@ EXPORTS
     ?SetWidth@FormatConversionSpecImplFriend@str_format_internal@absl@@SAXHPEAVFormatConversionSpecImpl@23@@Z
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QEAAXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QEAAXXZ
     ?SignalAll@CondVar@absl@@QEAAXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PEA_N@Z
@@ -2279,6 +2383,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SA_KXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
     ?SleepFor@absl@@YAXVDuration@1@@Z
     ?SlowLock@SpinLock@base_internal@absl@@AEAAXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AEAAXI@Z
@@ -2309,6 +2414,7 @@ EXPORTS
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@000@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@00@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@0@Z
+    ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@AEBVAlphaNum@1@@Z
     ?StrReplaceAll@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@4@@Z
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?StripAsciiWhitespace@absl@@YA?AVstring_view@1@V21@@Z
@@ -2317,6 +2423,7 @@ EXPORTS
     ?StrlenInternal@string_view@absl@@CA_KPEBD@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AEAAXI_K@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@_K11@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QEAAPEAUCordRep@23@_K0@Z
     ?Subcord@Cord@absl@@QEBA?AV12@_K0@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PEBV62@_K@Z
     ?SubtractSize@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QEAAX_K@Z
@@ -2386,6 +2493,7 @@ EXPORTS
     ?ToInt64Minutes@absl@@YA_JVDuration@1@@Z
     ?ToInt64Nanoseconds@absl@@YA_JVDuration@1@@Z
     ?ToInt64Seconds@absl@@YA_JVDuration@1@@Z
+    ?ToOpResult@CordRepBtree@cord_internal@absl@@AEAA?AUOpResult@123@_N@Z
     ?ToString@?$BigUnsigned@$03@strings_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@?$BigUnsigned@$0FE@@strings_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@Status@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4StatusToStringMode@2@@Z
@@ -2822,6 +2930,7 @@ EXPORTS
     ?back@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransition@cctz@time_internal@absl@@XZ
     ?back@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUTransitionType@cctz@time_internal@absl@@XZ
     ?back@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAAAEAUViableSubstitution@strings_internal@absl@@XZ
+    ?back@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?base@?$__wrap_iter@PEAPEAVCordzHandle@cord_internal@absl@@@__1@std@@QEBAPEAPEAVCordzHandle@cord_internal@absl@@XZ
     ?base@?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@__1@std@@QEBAPEAUTransition@cctz@time_internal@absl@@XZ
     ?base@?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@__1@std@@QEBAPEAUTransitionType@cctz@time_internal@absl@@XZ
@@ -2835,6 +2944,7 @@ EXPORTS
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     ?begin@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAPEBUPayload@status_internal@2@XZ
     ?begin@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
+    ?begin@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?begin@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAA?AV?$__hash_iterator@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@23@XZ
     ?begin@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@XZ
     ?begin@?$initializer_list@PEAUCordRep@cord_internal@absl@@@std@@QEBAPEBQEAUCordRep@cord_internal@absl@@XZ
@@ -2848,8 +2958,13 @@ EXPORTS
     ?begin@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@23@XZ
     ?begin@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?begin@ChunkRange@Cord@absl@@QEBA?AVChunkIterator@23@XZ
+    ?begin@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?begin@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBAPEAPEAUCordRep@cord_internal@3@XZ
     ?begin@string_view@absl@@QEBAPEBDXZ
+    ?btree@CordRep@cord_internal@absl@@QEAAPEAVCordRepBtree@23@XZ
+    ?btree@CordRep@cord_internal@absl@@QEBAPEBVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeNavigator@cord_internal@absl@@QEBAPEAVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeReader@cord_internal@absl@@QEBAPEAVCordRepBtree@23@XZ
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     ?capacity@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@AEAV?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
@@ -2876,6 +2991,7 @@ EXPORTS
     ?capacity@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?capacity@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
+    ?capacity@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?capacity@CordRepRing@cord_internal@absl@@QEBAIXZ
     ?chunk_begin@Cord@absl@@QEBA?AVChunkIterator@12@XZ
     ?chunk_end@Cord@absl@@QEBA?AVChunkIterator@12@XZ
@@ -2904,9 +3020,9 @@ EXPORTS
     ?compare_exchange_weak@?$__atomic_base@PEAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QEAA_NAEAPEAUHashtablezInfo@container_internal@absl@@PEAU456@W4memory_order@23@2@Z
     ?concat@CordRep@cord_internal@absl@@QEAAPEAUCordRepConcat@23@XZ
     ?concat@CordRep@cord_internal@absl@@QEBAPEBUCordRepConcat@23@XZ
-    ?consumed@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
+    ?consumed@CordRepBtreeReader@cord_internal@absl@@QEBA_KXZ
     ?conversion_char@FormatConversionSpecImpl@str_format_internal@absl@@QEBA?AW4FormatConversionChar@3@XZ
-    ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cordz_info@InlineData@cord_internal@absl@@QEBAPEAVCordzInfo@23@XZ
     ?cordz_info@InlineRep@Cord@absl@@QEBAPEAVCordzInfo@cord_internal@3@XZ
     ?cordz_should_profile@cord_internal@absl@@YA_NXZ
@@ -2922,6 +3038,7 @@ EXPORTS
     ?data@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$Span@D@absl@@QEBAPEADXZ
     ?data@?$Span@I@absl@@QEBAPEAIXZ
+    ?data@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?data@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEAVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$vector@PEAUCordRep@cord_internal@absl@@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@__1@std@@QEBAPEBQEAUCordRep@cord_internal@absl@@XZ
     ?data@?$vector@PEAVCordzHandle@cord_internal@absl@@V?$allocator@PEAVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@QEBAPEBQEAVCordzHandle@cord_internal@absl@@XZ
@@ -3014,6 +3131,7 @@ EXPORTS
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEAAPEAUPayload@status_internal@2@XZ
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QEBAPEBUPayload@status_internal@2@XZ
     ?end@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBAPEBVFormatArgImpl@str_format_internal@2@XZ
+    ?end@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBAPEBQEAUCordRep@cord_internal@2@XZ
     ?end@?$__deque_base@PEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@IEAA?AV?$__deque_iterator@PEBVImpl@time_zone@cctz@time_internal@absl@@PEAPEBV12345@AEAPEBV12345@PEAPEAPEBV12345@_J$0A@@23@XZ
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     ?end@?$__split_buffer@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PEAPEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAPEAPEBVImpl@time_zone@cctz@time_internal@absl@@XZ
@@ -3026,6 +3144,7 @@ EXPORTS
     ?end@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransition@cctz@time_internal@absl@@@23@XZ
     ?end@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA?AV?$__wrap_iter@PEAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?end@ChunkRange@Cord@absl@@QEBA?AVChunkIterator@23@XZ
+    ?end@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?end@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBAPEAPEAUCordRep@cord_internal@3@XZ
     ?end@string_view@absl@@QEBAPEBDXZ
     ?entries@CordRepRing@cord_internal@absl@@QEBAIII@Z
@@ -3033,7 +3152,6 @@ EXPORTS
     ?entry_begin_pos@CordRepRing@cord_internal@absl@@QEBAAEB_KI@Z
     ?entry_child@CordRepRing@cord_internal@absl@@AEAAPEAPEAUCordRep@23@XZ
     ?entry_child@CordRepRing@cord_internal@absl@@QEBAAEBQEAUCordRep@23@I@Z
-    ?entry_data@CordRepRing@cord_internal@absl@@QEBA?AVstring_view@3@I@Z
     ?entry_data_offset@CordRepRing@cord_internal@absl@@AEAAPEAIXZ
     ?entry_data_offset@CordRepRing@cord_internal@absl@@QEBAAEBII@Z
     ?entry_end_offset@CordRepRing@cord_internal@absl@@QEBA_KI@Z
@@ -3046,6 +3164,7 @@ EXPORTS
     ?exchange@?$__atomic_base@P6AXAEBUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QEAAP6AXAEBUHashtablezInfo@container_internal@absl@@@ZP6AX0@ZW4memory_order@23@@Z
     ?external@CordRep@cord_internal@absl@@QEAAPEAUCordRepExternal@23@XZ
     ?external@CordRep@cord_internal@absl@@QEBAPEBUCordRepExternal@23@XZ
+    ?fetch_add_end@CordRepBtree@cord_internal@absl@@AEAA_K_K@Z
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     ?find@string_view@absl@@QEBA_KD_K@Z
     ?find@string_view@absl@@QEBA_KV12@_K@Z
@@ -3167,9 +3286,11 @@ EXPORTS
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     ?head@CordRepRing@cord_internal@absl@@QEBAIXZ
     ?head@Filler@CordRepRing@cord_internal@absl@@QEBAIXZ
+    ?height@CordRepBtree@cord_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Uhour_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?hour@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
+    ?index@CordRepBtree@cord_internal@absl@@QEBA_KW4EdgeType@123@@Z
     ?inline_size@InlineData@cord_internal@absl@@QEBA_KXZ
     ?inline_size@InlineRep@Cord@absl@@AEBA_KXZ
     ?is_basic@FormatConversionSpecImpl@str_format_internal@absl@@QEBA_NXZ
@@ -3186,7 +3307,7 @@ EXPORTS
     ?is_tree@InlineRep@Cord@absl@@QEBA_NXZ
     ?key_eq@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAAEAV?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@XZ
     ?length@?$Span@D@absl@@QEBA_KXZ
-    ?length@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
+    ?length@CordRepBtreeReader@cord_internal@absl@@QEBA_KXZ
     ?length@string_view@absl@@QEBA_KXZ
     ?load@?$__atomic_base@P6AXAEBUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QEBAP6AXAEBUHashtablezInfo@container_internal@absl@@@ZW4memory_order@23@@Z
     ?load@?$__atomic_base@PEAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QEBAPEAUHashtablezInfo@container_internal@absl@@W4memory_order@23@@Z
@@ -3301,7 +3422,6 @@ EXPORTS
     ?release@?$unique_ptr@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@23@@__1@std@@QEAAPEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@23@XZ
     ?release@?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QEAAPEAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@XZ
     ?release@?$unique_ptr@VTimeZoneInfo@cctz@time_internal@absl@@U?$default_delete@VTimeZoneInfo@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAAPEAVTimeZoneInfo@cctz@time_internal@absl@@XZ
-    ?remaining@CordRepRingReader@cord_internal@absl@@QEBA_KXZ
     ?remove_prefix@InlineRep@Cord@absl@@QEAAX_K@Z
     ?remove_prefix@string_view@absl@@QEAAX_K@Z
     ?remove_suffix@string_view@absl@@QEAAX_K@Z
@@ -3325,7 +3445,6 @@ EXPORTS
     ?rfind@string_view@absl@@QEBA_KV12@_K@Z
     ?ring@CordRep@cord_internal@absl@@QEAAPEAVCordRepRing@23@XZ
     ?ring@CordRep@cord_internal@absl@@QEBAPEBVCordRepRing@23@XZ
-    ?ring@CordRepRingReader@cord_internal@absl@@QEBAPEAVCordRepRing@23@XZ
     ?safe_strto128_base@numbers_internal@absl@@YA_NVstring_view@2@PEAVint128@2@H@Z
     ?safe_strto32_base@numbers_internal@absl@@YA_NVstring_view@2@PEAHH@Z
     ?safe_strto64_base@numbers_internal@absl@@YA_NVstring_view@2@PEA_JH@Z
@@ -3376,11 +3495,13 @@ EXPORTS
     ?second@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?second@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QEBAHXZ
     ?set_arg@BoundConversion@str_format_internal@absl@@QEAAXPEBVFormatArgImpl@23@@Z
+    ?set_begin@CordRepBtree@cord_internal@absl@@AEAAX_K@Z
     ?set_cordz_info@InlineData@cord_internal@absl@@QEAAXPEAVCordzInfo@23@@Z
     ?set_cordz_mean_interval@cord_internal@absl@@YAXH@Z
     ?set_data@InlineRep@Cord@absl@@QEAAPEAD_K@Z
     ?set_data@InlineRep@Cord@absl@@QEAAXPEBD_K_N@Z
     ?set_depth@CordRepConcat@cord_internal@absl@@QEAAXE@Z
+    ?set_end@CordRepBtree@cord_internal@absl@@AEAAX_K@Z
     ?set_from_arg@InputValue@UnboundConversion@str_format_internal@absl@@QEAAXH@Z
     ?set_inline_size@InlineData@cord_internal@absl@@QEAAX_K@Z
     ?set_inline_size@InlineRep@Cord@absl@@AEAAX_K@Z
@@ -3399,6 +3520,7 @@ EXPORTS
     ?size@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$Span@D@absl@@QEBA_KXZ
     ?size@?$Span@I@absl@@QEBA_KXZ
+    ?size@?$Span@QEAUCordRep@cord_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QEBA_KXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QEAAAEA_KXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PEAU?$__hash_node_base@PEAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PEAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QEBA_KXZ
@@ -3420,6 +3542,7 @@ EXPORTS
     ?size@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QEBA_KXZ
     ?size@AlphaNum@absl@@QEBA_KXZ
     ?size@Cord@absl@@QEBA_KXZ
+    ?size@CordRepBtree@cord_internal@absl@@QEBA_KXZ
     ?size@InlineRep@Cord@absl@@QEBA_KXZ
     ?size@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEBA_KXZ
     ?size@string_view@absl@@QEBA_KXZ
@@ -3431,6 +3554,7 @@ EXPORTS
     ?store@?$__atomic_base@W4OnDeadlockCycle@absl@@$0A@@__1@std@@QEAAXW4OnDeadlockCycle@absl@@W4memory_order@23@@Z
     ?store@?$__atomic_base@W4State@PerThreadSynch@base_internal@absl@@$0A@@__1@std@@QEAAXW4State@PerThreadSynch@base_internal@absl@@W4memory_order@23@@Z
     ?str@UntypedFormatSpecImpl@str_format_internal@absl@@QEBA?AVstring_view@3@XZ
+    ?sub_fetch_begin@CordRepBtree@cord_internal@absl@@AEAA_K_K@Z
     ?substr@string_view@absl@@QEBA?AV12@_K0@Z
     ?substring@CordRep@cord_internal@absl@@QEAAPEAUCordRepSubstring@23@XZ
     ?substring@CordRep@cord_internal@absl@@QEBAPEBUCordRepSubstring@23@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_x64_rel.def b/chromium/third_party/abseil-cpp/symbols_x64_rel.def
index a17fe1a8fd6..35bcb17f1a9 100644
--- a/chromium/third_party/abseil-cpp/symbols_x64_rel.def
+++ b/chromium/third_party/abseil-cpp/symbols_x64_rel.def
@@ -3,6 +3,12 @@ EXPORTS
     ??$?0V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAA@$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?MUsecond_tag@detail@cctz@time_internal@absl@@U01234@@detail@cctz@time_internal@absl@@YA_NAEBV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@0@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAPEBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAPEBD@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -62,12 +68,18 @@ EXPORTS
     ??$GenericCompare@HVstring_view@absl@@@absl@@YAHAEBVCord@0@AEBVstring_view@0@_K@Z
     ??$GenericCompare@_NVCord@absl@@@absl@@YA_NAEBVCord@0@0_K@Z
     ??$GenericCompare@_NVstring_view@absl@@@absl@@YA_NAEBVCord@0@AEBVstring_view@0@_K@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
     ??$ParseFloat@$09@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFloat@$0BA@@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFormatString@UParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@@str_format_internal@absl@@YA_NVstring_view@1@UParsedFormatConsumer@ParsedFormatBase@01@@Z
     ??$Prepend@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@0@AEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@3@@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YAHAEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@2@@Z
     ??$ToChronoDuration@V?$duration@JV?$ratio@$0DM@$00@__1@std@@@chrono@__1@std@@@time_internal@absl@@YA?AV?$duration@JV?$ratio@$0DM@$00@__1@std@@@chrono@__1@std@@VDuration@1@@Z
@@ -95,7 +107,6 @@ EXPORTS
     ??0?$__split_buffer@UTransition@cctz@time_internal@absl@@AEAV?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransition@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UViableSubstitution@strings_internal@absl@@AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@12@@Z
-    ??0AlphaNum@absl@@QEAA@PEBD@Z
     ??0AlphaNum@absl@@QEAA@UDec@1@@Z
     ??0AlphaNum@absl@@QEAA@UHex@1@@Z
     ??0AlphaNum@absl@@QEAA@_K@Z
@@ -103,6 +114,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QEAA@PEBX@Z
     ??0Arg@substitute_internal@absl@@QEAA@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QEAA@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@$$QEAV01@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@AEBV01@@Z
     ??0BadStatusOrAccess@absl@@QEAA@VStatus@1@@Z
     ??0BlockingCounter@absl@@QEAA@H@Z
     ??0ByAnyChar@absl@@QEAA@Vstring_view@1@@Z
@@ -147,6 +160,8 @@ EXPORTS
     ??1bad_optional_access@absl@@UEAA@XZ
     ??1bad_variant_access@absl@@UEAA@XZ
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IEAAAEAV012@$$QEAV012@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@AEBV01@@Z
     ??4Cord@absl@@QEAAAEAV01@Vstring_view@1@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVCord@0@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVStatus@0@@Z
@@ -172,6 +187,7 @@ EXPORTS
     ??ACord@absl@@QEBAD_K@Z
     ??BCord@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ??Bint128@absl@@QEBANXZ
+    ??EChunkIterator@Cord@absl@@QEAAAEAV012@XZ
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Hdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
@@ -201,7 +217,7 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPEBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AEAA?AV23@_K@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AEAAX_K@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceStack@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPEAX_K@Z
@@ -209,6 +225,7 @@ EXPORTS
     ?AlreadyExistsError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Append@Cord@absl@@QEAAX$$QEAV12@@Z
     ?Append@Cord@absl@@QEAAXAEBV12@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QEAAXVstring_view@3@@Z
@@ -218,6 +235,7 @@ EXPORTS
     ?AppendLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
     ?AppendPack@str_format_internal@absl@@YAAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?AppendTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -274,20 +292,24 @@ EXPORTS
     ?CompareSlowPath@Cord@absl@@AEBAHAEBV12@_K1@Z
     ?CompareSlowPath@Cord@absl@@AEBAHVstring_view@2@_K1@Z
     ?ConcatNodes@CordForest@absl@@QEAAPEAUCordRep@cord_internal@2@XZ
+    ?Consume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPEBDPEBD0PEAUUnboundConversion@12@PEAH@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAC_K@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAW4ctrl_t@12@_K@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QEAA_NAEBUUnboundConversion@34@Vstring_view@4@@Z
     ?Copy@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@II_K@Z
     ?CopyCordToString@absl@@YAXAEBVCord@1@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
     ?CopyTo@InlineRep@Cord@absl@@QEBAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@AEBAXPEAD@Z
     ?Crash@Helper@internal_statusor@absl@@SAXAEBVStatus@3@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K11@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPEAUThreadIdentity@base_internal@2@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPEAUThreadIdentity@12@XZ
@@ -310,6 +332,8 @@ EXPORTS
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AEAAXXZ
     ?DestroyCordSlow@Cord@absl@@AEAAXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QEAA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QEBA_NPEBV123@@Z
@@ -322,6 +346,9 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPEBX_J@Z@base_internal@absl@@CAXPEBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PEBDHPEAPEADPEAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PEBDHPEAPEADPEAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPEAXQEBQEAXQEAHHH_NP6AXPEBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
@@ -414,8 +441,11 @@ EXPORTS
     ?FromTM@absl@@YA?AVTime@1@AEBUtm@@VTimeZone@1@@Z
     ?FromUDate@absl@@YA?AVTime@1@N@Z
     ?FromUniversal@absl@@YA?AVTime@1@_J@Z
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AEAA?AV?$Span@D@3@_K@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QEBAD_K@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QEBAD_K@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QEBA?AUCordzStatistics@23@XZ
     ?GetCurrentTimeNanos@absl@@YA_JXZ
@@ -454,7 +484,7 @@ EXPORTS
     ?IncrementSynchSem@Mutex@absl@@CAXPEAV12@PEAUPerThreadSynch@base_internal@2@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXAEBV123@@Z
-    ?InitTree@ChunkIterator@Cord@absl@@AEAAXPEAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@AEBAXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AEAAXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PEAUCordRepExternal@12@@Z
     ?InitializeSymbolizer@absl@@YAXPEBD@Z
@@ -470,6 +500,8 @@ EXPORTS
     ?IsDataLoss@absl@@YA_NAEBVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NAEBVStatus@1@@Z
     ?IsFailedPrecondition@absl@@YA_NAEBVStatus@1@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
     ?IsInternal@absl@@YA_NAEBVStatus@1@@Z
     ?IsInvalidArgument@absl@@YA_NAEBVStatus@1@@Z
     ?IsNotFound@absl@@YA_NAEBVStatus@1@@Z
@@ -481,6 +513,7 @@ EXPORTS
     ?IsUnavailable@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnknown@absl@@YA_NAEBVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPEBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QEBA_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?Iterate@HashtablezSampler@container_internal@absl@@QEAA_JAEBV?$function@$$A6AXAEBUHashtablezInfo@container_internal@absl@@@Z@__1@std@@@Z
     ?LengthModToString@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4LengthMod@12@@Z
@@ -508,6 +541,7 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAEAVInlineData@23@AEBV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CA_KPEBUCordRep@cord_internal@2@@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@0@Z
     ?MovedFromString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AEAAXHPEBI@Z
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@QEAAXI@Z
@@ -526,7 +560,6 @@ EXPORTS
     ?New@CordRepFlat@cord_internal@absl@@SAPEAU123@_K@Z
     ?New@CordRepRing@cord_internal@absl@@CAPEAV123@_K0@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QEBAPEAV123@AEBVCordzSnapshot@23@@Z
     ?NextTransition@TimeZone@absl@@QEBA_NVTime@2@PEAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
@@ -565,9 +598,11 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AEAAXXZ
     ?Prepend@Cord@absl@@QEAAXAEBV12@@Z
     ?Prepend@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -582,6 +617,8 @@ EXPORTS
     ?PutPaddedString@FormatSinkImpl@str_format_internal@absl@@QEAA_NVstring_view@3@HH_N@Z
     ?RawLog@raw_logging_internal@absl@@YAXW4LogSeverity@2@PEBDH1ZZ
     ?RawLoggingFullySupported@raw_logging_internal@absl@@YA_NXZ
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUReadResult@123@_K0@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K0AEAPEAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QEAAHAEBUParsedFloat@23@H@Z
@@ -616,10 +653,11 @@ EXPORTS
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AEAA_NAEBV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QEBA_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPEBD_K@Z
     ?SampleSlow@container_internal@absl@@YAPEAUHashtablezInfo@12@PEA_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
     ?SetCapacityForTesting@CordRepRing@cord_internal@absl@@QEAAX_K@Z
     ?SetCurrentThreadIdentity@base_internal@absl@@YAXPEAUThreadIdentity@12@P6AXPEAX@Z@Z
     ?SetDisposeCallback@HashtablezSampler@container_internal@absl@@QEAAP6AXAEBUHashtablezInfo@23@@ZP6AX0@Z@Z
@@ -635,7 +673,7 @@ EXPORTS
     ?SetToZero@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXXZ
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QEAAXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QEAAXXZ
     ?SignalAll@CondVar@absl@@QEAAXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PEA_N@Z
@@ -645,6 +683,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SA_KXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
     ?SlowLock@SpinLock@base_internal@absl@@AEAAXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AEAAXI@Z
     ?SnprintF@str_format_internal@absl@@YAHPEAD_KVUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -665,6 +704,7 @@ EXPORTS
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AEAAXI_K@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@_K11@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QEAAPEAUCordRep@23@_K0@Z
     ?Subcord@Cord@absl@@QEBA?AV12@_K0@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PEBV62@_K@Z
     ?Summarize@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -790,8 +830,11 @@ EXPORTS
     ?__swap_out_circular_buffer@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@AEAAPEAUTransitionType@cctz@time_internal@absl@@AEAU?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@23@PEAU4567@@Z
     ?__vallocate@?$vector@PEAUCordRep@cord_internal@absl@@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@__1@std@@AEAAX_K@Z
     ?__vallocate@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@AEAAX_K@Z
+    ?chunk_begin@Cord@absl@@QEBA?AVChunkIterator@12@XZ
     ?clear@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAXXZ
     ?code@Status@absl@@QEBA?AW4StatusCode@2@XZ
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_exhaustive_validation@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?day_difference@impl@detail@cctz@time_internal@absl@@YA_J_JCC0CC@Z
     ?description@time_zone@cctz@time_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_x64_rel_asan.def b/chromium/third_party/abseil-cpp/symbols_x64_rel_asan.def
index 71e23e2b617..44d4b15b251 100644
--- a/chromium/third_party/abseil-cpp/symbols_x64_rel_asan.def
+++ b/chromium/third_party/abseil-cpp/symbols_x64_rel_asan.def
@@ -3,6 +3,12 @@ EXPORTS
     ??$?0V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAA@$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?MUsecond_tag@detail@cctz@time_internal@absl@@U01234@@detail@cctz@time_internal@absl@@YA_NAEBV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@0@Z
     ??$?RW4LogSeverity@absl@@AEBQEBDHAEAPEBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PEBDHAEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QEBAX$$QEAW4LogSeverity@2@AEBQEBD$$QEAHAEAPEBD@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@PEAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AEAA?AVstring_view@2@V32@_K@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@Vstring_view@2@_K@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPEAV012@PEAV012@0_K1@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -11,7 +17,6 @@ EXPORTS
     ??$Base64EscapeInternal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEBE_KPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_NPEBD@Z
     ??$CallOnceImpl@A6AXXZ$$V@base_internal@absl@@YAXPEAU?$atomic@I@__1@std@@W4SchedulingMode@01@A6AXXZ@Z
     ??$CastAndCallFunction@$$CBU?$atomic@_N@__1@std@@@Condition@absl@@CA_NPEBV01@@Z
-    ??$Compare@$0FE@$0FE@@strings_internal@absl@@YAHAEBV?$BigUnsigned@$0FE@@01@0@Z
     ??$Dispatch@C@FormatArgImpl@str_format_internal@absl@@CA_NTData@012@VFormatConversionSpecImpl@12@PEAX@Z
     ??$Dispatch@D@FormatArgImpl@str_format_internal@absl@@CA_NTData@012@VFormatConversionSpecImpl@12@PEAX@Z
     ??$Dispatch@E@FormatArgImpl@str_format_internal@absl@@CA_NTData@012@VFormatConversionSpecImpl@12@PEAX@Z
@@ -62,12 +67,18 @@ EXPORTS
     ??$GenericCompare@HVstring_view@absl@@@absl@@YAHAEBVCord@0@AEBVstring_view@0@_K@Z
     ??$GenericCompare@_NVCord@absl@@@absl@@YA_NAEBVCord@0@0_K@Z
     ??$GenericCompare@_NVstring_view@absl@@@absl@@YA_NAEBVCord@0@AEBVstring_view@0@_K@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@PEAV012@0@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPEAV012@Vstring_view@2@_K@Z
     ??$ParseFloat@$09@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFloat@$0BA@@strings_internal@absl@@YA?AUParsedFloat@01@PEBD0W4chars_format@1@@Z
     ??$ParseFormatString@UParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@@str_format_internal@absl@@YA_NVstring_view@1@UParsedFormatConsumer@ParsedFormatBase@01@@Z
     ??$Prepend@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QEAAX$$QEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@_K@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QEAA?AUOpResult@012@_NPEAUCordRep@12@_K@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@0@AEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@3@@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YAHAEBV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@2@@Z
     ??$ToChronoDuration@V?$duration@JV?$ratio@$0DM@$00@__1@std@@@chrono@__1@std@@@time_internal@absl@@YA?AV?$duration@JV?$ratio@$0DM@$00@__1@std@@@chrono@__1@std@@VDuration@1@@Z
@@ -99,7 +110,6 @@ EXPORTS
     ??0?$__split_buffer@UTransition@cctz@time_internal@absl@@AEAV?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransition@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UTransitionType@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UViableSubstitution@strings_internal@absl@@AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QEAA@_K0AEAV?$allocator@UViableSubstitution@strings_internal@absl@@@12@@Z
-    ??0AlphaNum@absl@@QEAA@PEBD@Z
     ??0AlphaNum@absl@@QEAA@UDec@1@@Z
     ??0AlphaNum@absl@@QEAA@UHex@1@@Z
     ??0AlphaNum@absl@@QEAA@_K@Z
@@ -107,6 +117,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QEAA@PEBX@Z
     ??0Arg@substitute_internal@absl@@QEAA@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QEAA@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@$$QEAV01@@Z
+    ??0BadStatusOrAccess@absl@@QEAA@AEBV01@@Z
     ??0BadStatusOrAccess@absl@@QEAA@VStatus@1@@Z
     ??0BlockingCounter@absl@@QEAA@H@Z
     ??0ByAnyChar@absl@@QEAA@Vstring_view@1@@Z
@@ -158,6 +170,8 @@ EXPORTS
     ??1bad_optional_access@absl@@UEAA@XZ
     ??1bad_variant_access@absl@@UEAA@XZ
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IEAAAEAV012@$$QEAV012@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@$$QEAV01@@Z
+    ??4BadStatusOrAccess@absl@@QEAAAEAV01@AEBV01@@Z
     ??4Cord@absl@@QEAAAEAV01@Vstring_view@1@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVCord@0@@Z
     ??6absl@@YAAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AEAV123@AEBVStatus@0@@Z
@@ -183,6 +197,7 @@ EXPORTS
     ??ACord@absl@@QEBAD_K@Z
     ??BCord@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ??Bint128@absl@@QEBANXZ
+    ??EChunkIterator@Cord@absl@@QEAAAEAV012@XZ
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Gdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
     ??Hdetail@cctz@time_internal@absl@@YA?AV?$civil_time@Uday_tag@detail@cctz@time_internal@absl@@@0123@V40123@_J@Z
@@ -212,7 +227,7 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPEBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AEAA?AV23@_K@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AEAAX_K@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AEAAX_K@Z
     ?AdvanceStack@ChunkIterator@Cord@absl@@AEAAAEAV123@XZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPEAX_K@Z
@@ -222,6 +237,7 @@ EXPORTS
     ?AnnotateDestruct@NonEmptyInlinedStorage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QEAAX_K@Z
     ?Append@Cord@absl@@QEAAX$$QEAV12@@Z
     ?Append@Cord@absl@@QEAAXAEBV12@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QEAAXVstring_view@3@@Z
@@ -231,6 +247,7 @@ EXPORTS
     ?AppendLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
     ?AppendPack@str_format_internal@absl@@YAAEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?AppendTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?AppendTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -287,19 +304,23 @@ EXPORTS
     ?CompareSlowPath@Cord@absl@@AEBAHAEBV12@_K1@Z
     ?CompareSlowPath@Cord@absl@@AEBAHVstring_view@2@_K1@Z
     ?ConcatNodes@CordForest@absl@@QEAAPEAUCordRep@cord_internal@2@XZ
+    ?Consume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPEBDPEBD0PEAUUnboundConversion@12@PEAH@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAC_K@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPEAW4ctrl_t@12@_K@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOAEBVFormatConversionSpecImpl@12@PEAVFormatSinkImpl@12@@Z
     ?Copy@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@II_K@Z
     ?CopyCordToString@absl@@YAXAEBVCord@1@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AEAA?AUCopyResult@123@_K@Z
     ?CopyTo@InlineRep@Cord@absl@@QEBAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@AEBAXPEAD@Z
     ?Crash@Helper@internal_statusor@absl@@SAXAEBVStatus@3@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K11@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAUCordRep@23@_K@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPEAUThreadIdentity@base_internal@2@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPEAUThreadIdentity@12@XZ
@@ -322,6 +343,8 @@ EXPORTS
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AEAAXXZ
     ?DestroyCordSlow@Cord@absl@@AEAAXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPEAV123@_K1@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QEAA?AV?$vector@PEBVCordzHandle@cord_internal@absl@@V?$allocator@PEBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QEBA_NPEBV123@@Z
@@ -334,6 +357,9 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPEBX_J@Z@base_internal@absl@@CAXPEBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PEBDHPEAPEADPEAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PEBDHPEAPEADPEAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@AEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPEBUCordRep@23@Vstring_view@3@_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPEAXQEBQEAXQEAHHH_NP6AXPEBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
@@ -427,8 +453,11 @@ EXPORTS
     ?FromTM@absl@@YA?AVTime@1@AEBUtm@@VTimeZone@1@@Z
     ?FromUDate@absl@@YA?AVTime@1@N@Z
     ?FromUniversal@absl@@YA?AVTime@1@_J@Z
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QEAA?AV?$Span@D@3@_K@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AEAA?AV?$Span@D@3@_K@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QEBAD_K@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QEBAD_K@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QEBA?AUCordzStatistics@23@XZ
     ?GetCurrentTimeNanos@absl@@YA_JXZ
@@ -467,7 +496,7 @@ EXPORTS
     ?IncrementSynchSem@Mutex@absl@@CAXPEAV12@PEAUPerThreadSynch@base_internal@2@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPEAUThreadIdentity@base_internal@3@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QEAAXAEBV123@@Z
-    ?InitTree@ChunkIterator@Cord@absl@@AEAAXPEAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@AEBAXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AEAAXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PEAUCordRepExternal@12@@Z
     ?InitializeData@Storage@?$FixedArray@PEAUCordRep@cord_internal@absl@@$0?0V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@absl@@AEAAPEAPEAUCordRep@cord_internal@3@XZ
@@ -484,6 +513,8 @@ EXPORTS
     ?IsDataLoss@absl@@YA_NAEBVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NAEBVStatus@1@@Z
     ?IsFailedPrecondition@absl@@YA_NAEBVStatus@1@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_NPEAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QEBA_N_K0PEAVstring_view@3@@Z
     ?IsInternal@absl@@YA_NAEBVStatus@1@@Z
     ?IsInvalidArgument@absl@@YA_NAEBVStatus@1@@Z
     ?IsNotFound@absl@@YA_NAEBVStatus@1@@Z
@@ -495,6 +526,7 @@ EXPORTS
     ?IsUnavailable@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NAEBVStatus@1@@Z
     ?IsUnknown@absl@@YA_NAEBVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPEBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QEBA_NAEAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?Iterate@HashtablezSampler@container_internal@absl@@QEAA_JAEBV?$function@$$A6AXAEBUHashtablezInfo@container_internal@absl@@@Z@__1@std@@@Z
     ?LengthModToString@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4LengthMod@12@@Z
@@ -522,6 +554,7 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAEAVInlineData@23@AEBV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CA_KPEBUCordRep@cord_internal@2@@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@0@Z
     ?MovedFromString@Status@absl@@CAPEBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AEAAXHPEBI@Z
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@QEAAXI@Z
@@ -540,7 +573,6 @@ EXPORTS
     ?New@CordRepFlat@cord_internal@absl@@SAPEAU123@_K@Z
     ?New@CordRepRing@cord_internal@absl@@CAPEAV123@_K0@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPEAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QEBAPEAV123@AEBVCordzSnapshot@23@@Z
     ?NextTransition@TimeZone@absl@@QEBA_NVTime@2@PEAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UEBA_NAEBV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PEAUcivil_transition@time_zone@234@@Z
@@ -579,9 +611,11 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AEAAXXZ
     ?Prepend@Cord@absl@@QEAAXAEBV12@@Z
     ?Prepend@Cord@absl@@QEAAXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@Vstring_view@3@_K@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@_K2@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPEAV123@PEAV123@PEAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QEAAXPEAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -596,6 +630,8 @@ EXPORTS
     ?PutPaddedString@FormatSinkImpl@str_format_internal@absl@@QEAA_NVstring_view@3@HH_N@Z
     ?RawLog@raw_logging_internal@absl@@YAXW4LogSeverity@2@PEBDH1ZZ
     ?RawLoggingFullySupported@raw_logging_internal@absl@@YA_NXZ
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUReadResult@123@_K0@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K0AEAPEAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AEAAHPEBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QEAAHAEBUParsedFloat@23@H@Z
@@ -630,10 +666,11 @@ EXPORTS
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AEAA_NAEBV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPEAUCordRep@12@V?$FunctionRef@$$A6AXPEAUCordRep@cord_internal@absl@@_K1@Z@2@@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QEBA_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPEBD_K@Z
     ?SampleSlow@container_internal@absl@@YAPEAUHashtablezInfo@12@PEA_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QEAA?AVstring_view@3@_K@Z
     ?SetCapacityForTesting@CordRepRing@cord_internal@absl@@QEAAX_K@Z
     ?SetCurrentThreadIdentity@base_internal@absl@@YAXPEAUThreadIdentity@12@P6AXPEAX@Z@Z
     ?SetDisposeCallback@HashtablezSampler@container_internal@absl@@QEAAP6AXAEBUHashtablezInfo@23@@ZP6AX0@Z@Z
@@ -649,7 +686,7 @@ EXPORTS
     ?SetToZero@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXXZ
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QEAAXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QEAAXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_N_KPEBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QEAAXXZ
     ?SignalAll@CondVar@absl@@QEAAXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PEA_N@Z
@@ -659,6 +696,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SA_KXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SA_KXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QEAA?AUPosition@123@_K@Z
     ?SlowLock@SpinLock@base_internal@absl@@AEAAXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AEAAXI@Z
     ?SnprintF@str_format_internal@absl@@YAHPEAD_KVUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -679,6 +717,7 @@ EXPORTS
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AEAAXI_K@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPEAV123@PEAV123@_K11@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QEAAPEAUCordRep@23@_K0@Z
     ?Subcord@Cord@absl@@QEBA?AV12@_K0@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPEAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PEBV62@_K@Z
     ?Summarize@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -838,8 +877,11 @@ EXPORTS
     ?__vallocate@?$vector@PEAUCordRep@cord_internal@absl@@V?$allocator@PEAUCordRep@cord_internal@absl@@@__1@std@@@__1@std@@AEAAX_K@Z
     ?__vallocate@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@AEAAX_K@Z
     ?__vdeallocate@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@AEAAXXZ
+    ?chunk_begin@Cord@absl@@QEBA?AVChunkIterator@12@XZ
     ?clear@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PEBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QEAAXXZ
     ?code@Status@absl@@QEBA?AW4StatusCode@2@XZ
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_exhaustive_validation@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?day_difference@impl@detail@cctz@time_internal@absl@@YA_J_JCC0CC@Z
     ?description@time_zone@cctz@time_internal@absl@@QEBA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_x86_dbg.def b/chromium/third_party/abseil-cpp/symbols_x86_dbg.def
index 1821ae43a48..a01d397247e 100644
--- a/chromium/third_party/abseil-cpp/symbols_x86_dbg.def
+++ b/chromium/third_party/abseil-cpp/symbols_x86_dbg.def
@@ -1,6 +1,7 @@
 EXPORTS
     ??$?0$$CBD$0A@@VoidPtr@str_format_internal@absl@@QAE@PBD@Z
     ??$?0$$CBU?$atomic@_N@__1@std@@@Condition@absl@@QAE@P6A_NPBU?$atomic@_N@__1@std@@@Z0@Z
+    ??$?0$$CBUCordRep@cord_internal@absl@@@Hex@absl@@QAE@PBUCordRep@cord_internal@1@W4PadSpec@1@@Z
     ??$?0$$CBVFormatArgImpl@str_format_internal@absl@@$$CBV012@@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QAE@V?$initializer_list@VFormatArgImpl@str_format_internal@absl@@@std@@@Z
     ??$?0$$T@?$Storage@PAH$00$0A@@internal_compressed_tuple@container_internal@absl@@QAE@Uin_place_t@3@$$QA$$T@Z
     ??$?0$$T@?$Storage@PAPAUCordRep@cord_internal@absl@@$00$0A@@internal_compressed_tuple@container_internal@absl@@QAE@Uin_place_t@3@$$QA$$T@Z
@@ -55,7 +56,6 @@ EXPORTS
     ??$?0AAPAPBVImpl@time_zone@cctz@time_internal@absl@@X@?$__compressed_pair_elem@PAPBVImpl@time_zone@cctz@time_internal@absl@@$0A@$0A@@__1@std@@QAE@AAPAPBVImpl@time_zone@cctz@time_internal@absl@@@Z
     ??$?0AAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@12@@?$__compressed_pair@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@23@@__1@std@@QAE@AAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@12@$$QAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@12@@Z
     ??$?0AAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@X@?$__compressed_pair_elem@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@$0A@$0A@@__1@std@@QAE@AAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@12@@Z
-    ??$?0AAPAUCordRep@cord_internal@absl@@AAPAU012@$0A@@?$pair@PAUCordRep@cord_internal@absl@@PAU123@@__1@std@@QAE@AAPAUCordRep@cord_internal@absl@@0@Z
     ??$?0AAPAUThreadIdentity@base_internal@absl@@ABQ6AXPAX@Z@?$__compressed_pair@PAUThreadIdentity@base_internal@absl@@P6AXPAX@Z@__1@std@@QAE@AAPAUThreadIdentity@base_internal@absl@@ABQ6AXPAX@Z@Z
     ??$?0AAPAUThreadIdentity@base_internal@absl@@X@?$__compressed_pair_elem@PAUThreadIdentity@base_internal@absl@@$0A@$0A@@__1@std@@QAE@AAPAUThreadIdentity@base_internal@absl@@@Z
     ??$?0AAPAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U__default_init_tag@__1@std@@@?$__compressed_pair@PAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QAE@AAPAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$QAU__default_init_tag@12@@Z
@@ -221,7 +221,19 @@ EXPORTS
     ??$?RW4LogSeverity@absl@@ABQBDHAAPBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PBDHABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QBEX$$QAW4LogSeverity@2@ABQBD$$QAHAAPBD@Z
     ??$?RW4LogSeverity@absl@@ABQBDHAAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PBDHABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QBEX$$QAW4LogSeverity@2@ABQBD$$QAHAAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?RW4LogSeverity@absl@@ABQBDHV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@?$AtomicHook@P6AXW4LogSeverity@absl@@PBDHABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QBEX$$QAW4LogSeverity@2@ABQBD$$QAH$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
-    ??$?XH@Duration@absl@@QAEAAV01@H@Z
+    ??$?XH$0A@@Duration@absl@@QAEAAV01@H@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AAEXPAUCordRep@12@@Z
+    ??$Add@$00@CordRepBtree@cord_internal@absl@@AAEXV?$Span@QAUCordRep@cord_internal@absl@@@2@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AAEXPAUCordRep@12@@Z
+    ??$Add@$0A@@CordRepBtree@cord_internal@absl@@AAEXV?$Span@QAUCordRep@cord_internal@absl@@@2@@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@PAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@PAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AAE?AVstring_view@2@V32@I@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@Vstring_view@2@I@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AAE?AVstring_view@2@V32@I@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@Vstring_view@2@I@Z
+    ??$AddEdge@$00@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
+    ??$AddEdge@$0A@@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPAV012@PAV012@0II@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPAV012@PAV012@0II@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QAEX$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -350,6 +362,8 @@ EXPORTS
     ??$HidePtr@$$CBX@base_internal@absl@@YAIPBX@Z
     ??$HidePtr@U?$atomic@H@__1@std@@@base_internal@absl@@YAIPAU?$atomic@H@__1@std@@@Z
     ??$HidePtr@X@base_internal@absl@@YAIPAX@Z
+    ??$Hours@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Init@$0A@@CordRepBtreeNavigator@cord_internal@absl@@AAEPAUCordRep@12@PAVCordRepBtree@12@@Z
     ??$Init@H@FormatArgImpl@str_format_internal@absl@@AAEXABH@Z
     ??$Initialize@V?$CopyValueAdapter@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@@?$Storage@PAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXV?$CopyValueAdapter@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@12@I@Z
     ??$Invoke@A6AXXZ$$V@Callable@base_internal@absl@@SAXA6AXXZ@Z
@@ -365,7 +379,19 @@ EXPORTS
     ??$MakeSpan@$SI$0CIA@@absl@@YA?AV?$Span@I@0@AAY0CIA@I@Z
     ??$MakeSpan@$SI$0IA@@absl@@YA?AV?$Span@I@0@AAY0IA@I@Z
     ??$MakeSpan@$SVFormatArgImpl@str_format_internal@absl@@@absl@@YA?AV?$Span@VFormatArgImpl@str_format_internal@absl@@@0@PAVFormatArgImpl@str_format_internal@0@I@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@0@Z
+    ??$Microseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Microseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Milliseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Milliseconds@K$0A@@absl@@YA?AVDuration@0@K@Z
     ??$Milliseconds@N$0A@@absl@@YA?AVDuration@0@N@Z
+    ??$Minutes@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Nanoseconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Nanoseconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPAV012@Vstring_view@2@I@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@Vstring_view@2@I@Z
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@IPAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@I$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QBEIXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@IPAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@I$0A@$00@absl@@U?$integer_sequence@I$0A@$00$01@5@@internal_layout@container_internal@absl@@QBEIXZ
     ??$Offset@$00$0A@@?$LayoutImpl@V?$tuple@IPAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@I$0A@@absl@@U?$integer_sequence@I$0A@$00@5@@internal_layout@container_internal@absl@@QBEIXZ
@@ -393,6 +419,11 @@ EXPORTS
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
     ??$STLStringResizeUninitialized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
+    ??$Seconds@H$0A@@absl@@YA?AVDuration@0@H@Z
+    ??$Seconds@J$0A@@absl@@YA?AVDuration@0@J@Z
+    ??$Seconds@_J$0A@@absl@@YA?AVDuration@0@_J@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
     ??$SharedCompareImpl@VCord@absl@@@absl@@YAHABVCord@0@0@Z
     ??$SharedCompareImpl@Vstring_view@absl@@@absl@@YAHABVCord@0@ABVstring_view@0@@Z
     ??$StrAppend@$$V@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@ABVAlphaNum@0@1111@Z
@@ -639,7 +670,6 @@ EXPORTS
     ??$forward@AAPAPBUCordRep@cord_internal@absl@@@__1@std@@YAAAPAPBUCordRep@cord_internal@absl@@AAPAPBU234@@Z
     ??$forward@AAPAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@YAAAPAPBVImpl@time_zone@cctz@time_internal@absl@@AAPAPBV23456@@Z
     ??$forward@AAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@YAAAPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@01@AAPAU201@@Z
-    ??$forward@AAPAUCordRep@cord_internal@absl@@@__1@std@@YAAAPAUCordRep@cord_internal@absl@@AAPAU234@@Z
     ??$forward@AAPAUPayload@status_internal@absl@@@__1@std@@YAAAPAUPayload@status_internal@absl@@AAPAU234@@Z
     ??$forward@AAPAUSubRange@absl@@@__1@std@@YAAAPAUSubRange@absl@@AAPAU23@@Z
     ??$forward@AAPAUThreadIdentity@base_internal@absl@@@__1@std@@YAAAPAUThreadIdentity@base_internal@absl@@AAPAU234@@Z
@@ -740,7 +770,6 @@ EXPORTS
     ??$get@Vstring_view@absl@@V12@@?$__get_pair@$0A@@__1@std@@SAABVstring_view@absl@@ABU?$pair@Vstring_view@absl@@V12@@12@@Z
     ??$invoke@A6AXXZ$$V@base_internal@absl@@YAXA6AXXZ@Z
     ??$lower_bound@PBUTransition@cctz@time_internal@absl@@U1234@UByUnixTime@1234@@__1@std@@YAPBUTransition@cctz@time_internal@absl@@PBU2345@0ABU2345@UByUnixTime@2345@@Z
-    ??$make_pair@AAPAUCordRep@cord_internal@absl@@AAPAU123@@__1@std@@YA?AU?$pair@PAUCordRep@cord_internal@absl@@PAU123@@01@AAPAUCordRep@cord_internal@absl@@0@Z
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@$$V@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@XZ
     ??$make_unique@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@AAV12@@__1@std@@YA?AV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@Z
     ??$max_size@V?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@X@?$allocator_traits@V?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@SAIABV?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@12@@Z
@@ -777,6 +806,7 @@ EXPORTS
     ??$move@AAUTransition@cctz@time_internal@absl@@@__1@std@@YA$$QAUTransition@cctz@time_internal@absl@@AAU2345@@Z
     ??$move@AAUTransitionType@cctz@time_internal@absl@@@__1@std@@YA$$QAUTransitionType@cctz@time_internal@absl@@AAU2345@@Z
     ??$move@AAUViableSubstitution@strings_internal@absl@@@__1@std@@YA$$QAUViableSubstitution@strings_internal@absl@@AAU234@@Z
+    ??$move@AAV?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@absl@@@__1@std@@YA$$QAV?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@absl@@AAV23@@Z
     ??$move@AAV?$__allocator_destructor@V?$allocator@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QAV?$__allocator_destructor@V?$allocator@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@01@AAV201@@Z
     ??$move@AAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@YA$$QAV?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@01@AAV201@@Z
     ??$move@AAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@__1@std@@YA$$QAV?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@01@AAV201@@Z
@@ -838,7 +868,9 @@ EXPORTS
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QAE@PBVFormatArgImpl@str_format_internal@1@I@Z
     ??0?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QAE@XZ
     ??0?$Span@D@absl@@QAE@PADI@Z
+    ??0?$Span@D@absl@@QAE@XZ
     ??0?$Span@I@absl@@QAE@PAII@Z
+    ??0?$Span@QAUCordRep@cord_internal@absl@@@absl@@QAE@PBQAUCordRep@cord_internal@1@I@Z
     ??0?$Span@QAX@absl@@QAE@PBQAXI@Z
     ??0?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QAE@PAVFormatArgImpl@str_format_internal@1@I@Z
     ??0?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QAE@XZ
@@ -989,6 +1021,7 @@ EXPORTS
     ??0?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE@XZ
     ??0?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QAE@XZ
     ??0?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QAE@XZ
+    ??0AlphaNum@absl@@QAE@H@Z
     ??0AlphaNum@absl@@QAE@I@Z
     ??0AlphaNum@absl@@QAE@PBD@Z
     ??0AlphaNum@absl@@QAE@UDec@1@@Z
@@ -999,6 +1032,8 @@ EXPORTS
     ??0Arg@substitute_internal@absl@@QAE@PBX@Z
     ??0Arg@substitute_internal@absl@@QAE@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QAE@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QAE@$$QAV01@@Z
+    ??0BadStatusOrAccess@absl@@QAE@ABV01@@Z
     ??0BadStatusOrAccess@absl@@QAE@VStatus@1@@Z
     ??0BlockingCounter@absl@@QAE@H@Z
     ??0BoundConversion@str_format_internal@absl@@QAE@XZ
@@ -1021,11 +1056,13 @@ EXPORTS
     ??0Cord@absl@@QAE@XZ
     ??0CordForest@absl@@QAE@I@Z
     ??0CordRep@cord_internal@absl@@QAE@XZ
+    ??0CordRepBtree@cord_internal@absl@@AAE@XZ
+    ??0CordRepBtreeNavigator@cord_internal@absl@@QAE@XZ
+    ??0CordRepBtreeReader@cord_internal@absl@@QAE@XZ
     ??0CordRepConcat@cord_internal@absl@@QAE@XZ
     ??0CordRepExternal@cord_internal@absl@@QAE@XZ
     ??0CordRepFlat@cord_internal@absl@@QAE@XZ
     ??0CordRepRing@cord_internal@absl@@AAE@I@Z
-    ??0CordRepRingReader@cord_internal@absl@@QAE@XZ
     ??0CordRepSubstring@cord_internal@absl@@QAE@XZ
     ??0CordzHandle@cord_internal@absl@@IAE@_N@Z
     ??0CordzHandle@cord_internal@absl@@QAE@XZ
@@ -1042,9 +1079,10 @@ EXPORTS
     ??0FormatConversionSpecImpl@str_format_internal@absl@@QAE@XZ
     ??0FormatSinkImpl@str_format_internal@absl@@QAE@VFormatRawSinkImpl@12@@Z
     ??0GraphCycles@synchronization_internal@absl@@QAE@XZ
-    ??0GroupSse2Impl@container_internal@absl@@QAE@PBC@Z
+    ??0GroupSse2Impl@container_internal@absl@@QAE@PBW4ctrl_t@12@@Z
     ??0HashtablezInfo@container_internal@absl@@QAE@XZ
     ??0HashtablezSampler@container_internal@absl@@QAE@XZ
+    ??0Hex@absl@@AAE@W4PadSpec@1@_K@Z
     ??0Impl@time_zone@cctz@time_internal@absl@@AAE@ABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??0InlineData@cord_internal@absl@@QAE@W4DefaultInitType@012@@Z
     ??0InlineData@cord_internal@absl@@QAE@XZ
@@ -1073,6 +1111,7 @@ EXPORTS
     ??0SpinLock@base_internal@absl@@QAE@W4SchedulingMode@12@@Z
     ??0SpinLockHolder@base_internal@absl@@QAE@PAVSpinLock@12@@Z
     ??0Status@absl@@QAE@$$QAV01@@Z
+    ??0Status@absl@@QAE@ABV01@@Z
     ??0Status@absl@@QAE@W4StatusCode@1@Vstring_view@1@@Z
     ??0StatusRep@status_internal@absl@@QAE@W4StatusCode@2@Vstring_view@2@V?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@@Z
     ??0Storage@?$FixedArray@PAUCordRep@cord_internal@absl@@$0PPPPPPPP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QAE@IABV?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@Z
@@ -1115,6 +1154,8 @@ EXPORTS
     ??0int128@absl@@QAE@M@Z
     ??0int128@absl@@QAE@N@Z
     ??0int128@absl@@QAE@O@Z
+    ??0once_flag@absl@@QAE@XZ
+    ??0string_view@absl@@AAE@PBDIUSkipCheckLengthTag@01@@Z
     ??0string_view@absl@@QAE@PBD@Z
     ??0string_view@absl@@QAE@PBDI@Z
     ??0string_view@absl@@QAE@XZ
@@ -1238,12 +1279,15 @@ EXPORTS
     ??4?$optional@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@absl@@QAEAAV01@$$QAV01@@Z
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IAEAAV012@$$QAV012@@Z
     ??4?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QAEAAV012@$$QAV012@@Z
+    ??4BadStatusOrAccess@absl@@QAEAAV01@$$QAV01@@Z
+    ??4BadStatusOrAccess@absl@@QAEAAV01@ABV01@@Z
     ??4Cord@absl@@QAEAAV01@$$QAV01@@Z
     ??4Cord@absl@@QAEAAV01@Vstring_view@1@@Z
     ??4CordzUpdateTracker@cord_internal@absl@@QAEAAV012@ABV012@@Z
     ??4InlineRep@Cord@absl@@QAEAAV012@$$QAV012@@Z
     ??4Payload@status_internal@absl@@QAEAAU012@$$QAU012@@Z
     ??4Status@absl@@QAEAAV01@$$QAV01@@Z
+    ??4Status@absl@@QAEAAV01@ABV01@@Z
     ??4int128@absl@@QAEAAV01@H@Z
     ??4uint128@absl@@QAEAAV01@H@Z
     ??4uint128@absl@@QAEAAV01@_J@Z
@@ -1300,6 +1344,7 @@ EXPORTS
     ??A?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QBEABUPayload@status_internal@1@I@Z
     ??A?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QBEABVFormatArgImpl@str_format_internal@1@I@Z
     ??A?$Span@I@absl@@QBEAAII@Z
+    ??A?$array@PAUCordRep@cord_internal@absl@@$01@__1@std@@QAEAAPAUCordRep@cord_internal@absl@@I@Z
     ??A?$unique_ptr@$$BY0A@PAU?$__hash_node_base@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@V?$__bucket_list_deallocator@V?$allocator@PAU?$__hash_node_base@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@__1@std@@@23@@__1@std@@QBEAAPAU?$__hash_node_base@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@12@I@Z
     ??A?$unordered_map@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAEAAPBVImpl@time_zone@cctz@time_internal@absl@@ABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@12@@Z
     ??A?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEAAUTransition@cctz@time_internal@absl@@I@Z
@@ -1314,7 +1359,7 @@ EXPORTS
     ??B?$unique_ptr@VTimeZoneIf@cctz@time_internal@absl@@U?$default_delete@VTimeZoneIf@cctz@time_internal@absl@@@__1@std@@@__1@std@@QBE_NXZ
     ??B?$unique_ptr@VZoneInfoSource@cctz@time_internal@absl@@U?$default_delete@VZoneInfoSource@cctz@time_internal@absl@@@__1@std@@@__1@std@@QBE_NXZ
     ??BCord@absl@@QBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ??BCordRepRingReader@cord_internal@absl@@QBE_NXZ
+    ??BCordRepBtreeReader@cord_internal@absl@@QBE_NXZ
     ??BTimeZone@absl@@QBE?AVtime_zone@cctz@time_internal@1@XZ
     ??Bint128@absl@@QBEEXZ
     ??Bint128@absl@@QBENXZ
@@ -1438,6 +1483,7 @@ EXPORTS
     ??R<lambda_2>@?0???$AddRing@$00@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@0II@Z@QBE?A?<auto>@@I@Z
     ??R<lambda_2>@?0???$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@0II@Z@QBE?A?<auto>@@I@Z
     ??R<lambda_2>@?0??erase@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QAEPAUPayload@status_internal@3@PBU453@@Z@QBE?A?<auto>@@XZ
+    ??R?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@absl@@QBEXPAUCordRep@cord_internal@1@II@Z
     ??R?$FunctionRef@$$A6AXV?$Span@I@absl@@@Z@absl@@QBEXV?$Span@I@1@@Z
     ??R?$FunctionRef@$$A6AXVstring_view@absl@@@Z@absl@@QBEXVstring_view@1@@Z
     ??R?$__allocator_destructor@V?$allocator@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEXPAPBVImpl@time_zone@cctz@time_internal@absl@@@Z
@@ -1462,6 +1508,7 @@ EXPORTS
     ??RByCivilTime@Transition@cctz@time_internal@absl@@QBE_NABU1234@0@Z
     ??RByUnixTime@Transition@cctz@time_internal@absl@@QBE_NABU1234@0@Z
     ??Sabsl@@YA?AVuint128@0@V10@@Z
+    ??Uabsl@@YA?AVuint128@0@V10@0@Z
     ??Ustr_format_internal@absl@@YA?AW4Flags@01@W4201@0@Z
     ??XDuration@absl@@QAEAAV01@N@Z
     ??XDuration@absl@@QAEAAV01@_J@Z
@@ -1514,12 +1561,14 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AAEXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AAE?AV23@I@Z
+    ?AdvanceBtree@ChunkIterator@Cord@absl@@AAEAAV123@XZ
     ?AdvanceBytes@ChunkIterator@Cord@absl@@AAEXI@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AAEXI@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AAEXI@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AAEXI@Z
-    ?AdvanceRing@ChunkIterator@Cord@absl@@AAEAAV123@XZ
     ?AdvanceStack@ChunkIterator@Cord@absl@@AAEAAV123@XZ
     ?Align@adl_barrier@internal_layout@container_internal@absl@@YAIII@Z
+    ?AlignBegin@CordRepBtree@cord_internal@absl@@AAEXXZ
+    ?AlignEnd@CordRepBtree@cord_internal@absl@@AAEXXZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPAXI@Z
     ?AllocSize@?$LayoutImpl@V?$tuple@IPAUCordRep@cord_internal@absl@@I@__1@std@@U?$integer_sequence@I$0A@$00$01@absl@@U45@@internal_layout@container_internal@absl@@QBEIXZ
     ?AllocSize@CordRepRing@cord_internal@absl@@SAII@Z
@@ -1538,6 +1587,8 @@ EXPORTS
     ?Append@Cord@absl@@QAEX$$QAV12@@Z
     ?Append@Cord@absl@@QAEXABV12@@Z
     ?Append@Cord@absl@@QAEXVstring_view@2@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QAEXID@Z
@@ -1548,6 +1599,7 @@ EXPORTS
     ?AppendNode@CordForest@absl@@AAEPAUCordRep@cord_internal@2@PAU342@0@Z
     ?AppendPack@str_format_internal@absl@@YAAAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?AppendText@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QAEIVstring_view@4@@Z
     ?AppendTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -1561,6 +1613,8 @@ EXPORTS
     ?AssertHeld@Mutex@absl@@QBEXXZ
     ?AssertNotHeld@Mutex@absl@@QBEXXZ
     ?AssertReaderHeld@Mutex@absl@@QBEXXZ
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@_N@Z
+    ?AssertValid@CordRepBtree@cord_internal@absl@@SAPBV123@PBV123@_N@Z
     ?AssignLargeString@Cord@absl@@AAEAAV12@$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?AssignNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QAEXPAUPayload@status_internal@3@@Z
     ?AssignSlow@InlineRep@Cord@absl@@AAEXABV123@@Z
@@ -1625,28 +1679,39 @@ EXPORTS
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@PBUPayload@status_internal@absl@@@inlined_vector_internal@absl@@QAEXPAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@UPayload@status_internal@absl@@@__1@std@@V?$move_iterator@PAUPayload@status_internal@absl@@@23@@inlined_vector_internal@absl@@QAEXPAV?$allocator@UPayload@status_internal@absl@@@__1@std@@PAUPayload@status_internal@3@@Z
     ?ConstructNext@?$IteratorValueAdapter@V?$allocator@USubRange@absl@@@__1@std@@V?$move_iterator@PAUSubRange@absl@@@23@@inlined_vector_internal@absl@@QAEXPAV?$allocator@USubRange@absl@@@__1@std@@PAUSubRange@3@@Z
+    ?Consume@cord_internal@absl@@YAXPAUCordRep@12@V?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@2@@Z
     ?ConsumePrefix@absl@@YA_NPAVstring_view@1@V21@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPBDPBD0PAUUnboundConversion@12@PAH@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@D@Z
     ?Contains@str_format_internal@absl@@YA_NW4FormatConversionCharSet@2@W4FormatConversionChar@2@@Z
     ?ControlWord@base_internal@absl@@YAPAU?$atomic@I@__1@std@@PAVonce_flag@2@@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPACI@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPAW4ctrl_t@12@I@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QAE_NABUUnboundConversion@34@Vstring_view@4@@Z
-    ?ConvertSpecialToEmptyAndFullToDeleted@GroupSse2Impl@container_internal@absl@@QBEXPAC@Z
+    ?ConvertSpecialToEmptyAndFullToDeleted@GroupSse2Impl@container_internal@absl@@QBEXPAW4ctrl_t@23@@Z
+    ?Copy@CordRepBtree@cord_internal@absl@@ABEPAV123@XZ
     ?Copy@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@III@Z
+    ?CopyBeginTo@CordRepBtree@cord_internal@absl@@ABEPAV123@II@Z
     ?CopyCordToString@absl@@YAXABVCord@1@PAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AAE?AUCopyResult@123@I@Z
+    ?CopyRaw@CordRepBtree@cord_internal@absl@@ABEPAV123@XZ
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AAE?AUCopyResult@123@I@Z
     ?CopyTo@InlineRep@Cord@absl@@QBEXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@ABEXPAD@Z
+    ?CopyToEndFrom@CordRepBtree@cord_internal@absl@@ABEPAV123@II@Z
     ?Crash@Helper@internal_statusor@absl@@SAXABVStatus@3@@Z
+    ?Create@CordRepBtree@cord_internal@absl@@SAPAV123@PAUCordRep@23@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPAV123@PAUCordRep@23@I@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPAV123@PAUCordRep@23@III@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAUCordRep@23@I@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPAUThreadIdentity@base_internal@2@XZ
+    ?Current@CordRepBtreeNavigator@cord_internal@absl@@QBEPAUCordRep@23@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPAUThreadIdentity@12@XZ
+    ?Data@CordRepBtree@cord_internal@absl@@QBE?AVstring_view@3@I@Z
     ?Data@CordRepFlat@cord_internal@absl@@QAEPADXZ
     ?Data@CordRepFlat@cord_internal@absl@@QBEPBDXZ
     ?DataLength@Header@TimeZoneInfo@cctz@time_internal@absl@@QBEII@Z
@@ -1665,6 +1730,7 @@ EXPORTS
     ?DecrementSynchSem@Mutex@absl@@CA_NPAV12@PAUPerThreadSynch@base_internal@2@VKernelTimeout@synchronization_internal@2@@Z
     ?DefaultArena@LowLevelAlloc@base_internal@absl@@SAPAUArena@123@XZ
     ?DefaultStackUnwinder@absl@@YAHPAPAXPAHHHPBX1@Z
+    ?Delete@CordRepBtree@cord_internal@absl@@CAXPAV123@@Z
     ?Delete@CordRepExternal@cord_internal@absl@@SAXPAUCordRep@23@@Z
     ?Delete@CordRepFlat@cord_internal@absl@@SAXPAUCordRep@23@@Z
     ?Delete@CordRepRing@cord_internal@absl@@CAXPAV123@@Z
@@ -1675,10 +1741,14 @@ EXPORTS
     ?Description@TimeZoneInfo@cctz@time_internal@absl@@UBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Description@TimeZoneLibC@cctz@time_internal@absl@@UBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?Destroy@CordRep@cord_internal@absl@@SAXPAU123@@Z
+    ?Destroy@CordRepBtree@cord_internal@absl@@SAXPAV123@@Z
     ?Destroy@CordRepRing@cord_internal@absl@@CAXPAV123@@Z
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AAEXXZ
     ?DestroyCordSlow@Cord@absl@@AAEXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPAV123@II@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPAV123@II@Z
+    ?DestroyTree@CordRepBtree@cord_internal@absl@@CAXPAV123@II@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PBVCordzHandle@cord_internal@absl@@V?$allocator@PBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QAE?AV?$vector@PBVCordzHandle@cord_internal@absl@@V?$allocator@PBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QBE_NPBV123@@Z
@@ -1717,9 +1787,18 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPBX_J@Z@base_internal@absl@@CAXPBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PBDHPAPADPAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PBDHPAPADPAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@AAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@Vstring_view@3@AAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@Vstring_view@3@_NAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPAXQBQAXQAHHH_NP6AXPBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QBEPAUCordRep@23@I@Z
+    ?Edge@CordRepBtree@cord_internal@absl@@QBEPAUCordRep@23@W4EdgeType@123@@Z
+    ?EdgeData@CordRepBtree@cord_internal@absl@@SA?AVstring_view@3@PBUCordRep@23@@Z
+    ?EdgeDataPtr@CordRepBtree@cord_internal@absl@@SAPBDPBUCordRep@23@@Z
+    ?Edges@CordRepBtree@cord_internal@absl@@QBE?AV?$Span@QAUCordRep@cord_internal@absl@@@3@II@Z
+    ?Edges@CordRepBtree@cord_internal@absl@@QBE?AV?$Span@QAUCordRep@cord_internal@absl@@@3@XZ
     ?EmplaceTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@ABVInlineData@53@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmplaceTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?EmptyString@Status@absl@@CAPBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
@@ -1758,7 +1837,6 @@ EXPORTS
     ?Find@ByLength@absl@@QBE?AVstring_view@2@V32@I@Z
     ?Find@ByString@absl@@QBE?AVstring_view@2@V32@I@Z
     ?Find@CordRepRing@cord_internal@absl@@QBE?AUPosition@123@I@Z
-    ?Find@CordRepRing@cord_internal@absl@@QBE?AUPosition@123@II@Z
     ?FindFlatStartPiece@InlineRep@Cord@absl@@QBE?AVstring_view@3@XZ
     ?FindPath@GraphCycles@synchronization_internal@absl@@QBEHUGraphId@23@0HQAU423@@Z
     ?FindSlow@CordRepRing@cord_internal@absl@@ABE?AUPosition@123@II@Z
@@ -1860,13 +1938,16 @@ EXPORTS
     ?GetAllocator@?$AllocationTransaction@V?$allocator@PBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAV?$allocator@PBUCordRep@cord_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAV?$allocator@UPayload@status_internal@absl@@@__1@std@@XZ
     ?GetAllocator@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAV?$allocator@USubRange@absl@@@__1@std@@XZ
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QAE?AV?$Span@D@3@I@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QAE?AV?$Span@D@3@I@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AAE?AV?$Span@D@3@I@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QAEAAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@PBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAIXZ
     ?GetCapacity@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEAAIXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QBEDI@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QBEDI@Z
     ?GetCond@WinHelper@Waiter@synchronization_internal@absl@@SAPAU_RTL_CONDITION_VARIABLE@@PAV234@@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QBE?AUCordzStatistics@23@XZ
@@ -1950,28 +2031,34 @@ EXPORTS
     ?GetYearDay@absl@@YAHV?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@1@@Z
     ?Global@HashtablezSampler@container_internal@absl@@SAAAV123@XZ
     ?GuaranteedEqual@Condition@absl@@SA_NPBV12@0@Z
-    ?H1@container_internal@absl@@YAIIPBC@Z
+    ?H1@container_internal@absl@@YAIIPBW4ctrl_t@12@@Z
     ?HandleInvalidStatusCtorArg@Helper@internal_statusor@absl@@SAXPAVStatus@3@@Z
     ?HasBeenNotifiedInternal@Notification@absl@@CA_NPBU?$atomic@_N@__1@std@@@Z
     ?HasEdge@GraphCycles@synchronization_internal@absl@@QBE_NUGraphId@23@0@Z
     ?HasNode@GraphCycles@synchronization_internal@absl@@QAE_NUGraphId@23@@Z
-    ?HashSeed@container_internal@absl@@YAIPBC@Z
+    ?HashSeed@container_internal@absl@@YAIPBW4ctrl_t@12@@Z
     ?Head@CordzInfo@cord_internal@absl@@SAPAV123@ABVCordzSnapshot@23@@Z
     ?HexStringToBytes@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@@Z
     ?HideMask@base_internal@absl@@YAIXZ
-    ?Hours@absl@@YA?AVDuration@1@_J@Z
     ?IDivDuration@absl@@YA_JVDuration@1@0PAV21@@Z
     ?IDivDuration@time_internal@absl@@YA_J_NVDuration@2@1PAV32@@Z
     ?In@Time@absl@@QBE?AUBreakdown@12@VTimeZone@2@@Z
     ?InMillisecondsFromNow@KernelTimeout@synchronization_internal@absl@@ABEKXZ
     ?Increment@Refcount@cord_internal@absl@@QAEXXZ
     ?IncrementSynchSem@Mutex@absl@@CAXPAV12@PAUPerThreadSynch@base_internal@2@@Z
+    ?IndexBefore@CordRepBtree@cord_internal@absl@@ABE?AUPosition@123@U4123@I@Z
+    ?IndexBeyond@CordRepBtree@cord_internal@absl@@ABE?AUPosition@123@I@Z
+    ?IndexOf@CordRepBtree@cord_internal@absl@@ABE?AUPosition@123@I@Z
     ?InfiniteDuration@absl@@YA?AVDuration@1@XZ
     ?InfiniteFuture@absl@@YA?AVTime@1@XZ
     ?InfinitePast@absl@@YA?AVTime@1@XZ
+    ?Init@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@PAVCordRepBtree@23@@Z
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPAUThreadIdentity@base_internal@3@@Z
+    ?InitFirst@CordRepBtreeNavigator@cord_internal@absl@@QAEPAUCordRep@23@PAVCordRepBtree@23@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXABV123@@Z
+    ?InitInstance@CordRepBtree@cord_internal@absl@@AAEXHII@Z
     ?InitTree@ChunkIterator@Cord@absl@@AAEXPAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@ABEXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AAEXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PAUCordRepExternal@12@@Z
     ?InitializeData@Storage@?$FixedArray@PAUCordRep@cord_internal@absl@@$0PPPPPPPP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@absl@@AAEPAPAUCordRep@cord_internal@3@XZ
@@ -1990,14 +2077,19 @@ EXPORTS
     ?InvalidGraphId@synchronization_internal@absl@@YA?AUGraphId@12@XZ
     ?IsAborted@absl@@YA_NABVStatus@1@@Z
     ?IsAlreadyExists@absl@@YA_NABVStatus@1@@Z
+    ?IsBtree@CordRep@cord_internal@absl@@QBE_NXZ
     ?IsCancelled@absl@@YA_NABVStatus@1@@Z
+    ?IsConcat@CordRep@cord_internal@absl@@QBE_NXZ
     ?IsCooperative@SpinLock@base_internal@absl@@CA_NW4SchedulingMode@23@@Z
+    ?IsDataEdge@CordRepBtree@cord_internal@absl@@SA_NPBUCordRep@23@@Z
     ?IsDataLoss@absl@@YA_NABVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NABVStatus@1@@Z
     ?IsEmpty@Queue@CordzHandle@cord_internal@absl@@QBE_NXZ
+    ?IsExternal@CordRep@cord_internal@absl@@QBE_NXZ
     ?IsFailedPrecondition@absl@@YA_NABVStatus@1@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QBE_NIIPAVstring_view@3@@Z
-    ?IsFlat@CordRepRing@cord_internal@absl@@QBE_NPAVstring_view@3@@Z
+    ?IsFlat@CordRep@cord_internal@absl@@QBE_NXZ
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QBE_NIIPAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QBE_NPAVstring_view@3@@Z
     ?IsImmortal@Refcount@cord_internal@absl@@QBE_NXZ
     ?IsInfiniteDuration@time_internal@absl@@YA_NVDuration@2@@Z
     ?IsInlined@Status@absl@@CA_NI@Z
@@ -2010,11 +2102,14 @@ EXPORTS
     ?IsPermissionDenied@absl@@YA_NABVStatus@1@@Z
     ?IsReachable@GraphCycles@synchronization_internal@absl@@QBE_NUGraphId@23@0@Z
     ?IsResourceExhausted@absl@@YA_NABVStatus@1@@Z
+    ?IsRing@CordRep@cord_internal@absl@@QBE_NXZ
     ?IsSame@InlineRep@Cord@absl@@QBE_NABV123@@Z
+    ?IsSubstring@CordRep@cord_internal@absl@@QBE_NXZ
     ?IsUnauthenticated@absl@@YA_NABVStatus@1@@Z
     ?IsUnavailable@absl@@YA_NABVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NABVStatus@1@@Z
     ?IsUnknown@absl@@YA_NABVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QBE_NAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?IsValidCapacity@container_internal@absl@@YA_NI@Z
     ?IsValidIndex@CordRepRing@cord_internal@absl@@ABE_NI@Z
@@ -2066,10 +2161,8 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SAIXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAAVInlineData@23@ABV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CAIPBUCordRep@cord_internal@2@@Z
-    ?Microseconds@absl@@YA?AVDuration@1@_J@Z
-    ?Milliseconds@absl@@YA?AVDuration@1@_J@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@0@Z
     ?Min@string_view@absl@@CAIII@Z
-    ?Minutes@absl@@YA?AVDuration@1@_J@Z
     ?MovedFromRep@Status@absl@@CAIXZ
     ?MovedFromString@Status@absl@@CAPBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AAEXHPBI@Z
@@ -2087,13 +2180,16 @@ EXPORTS
     ?Mutable@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@I@Z
     ?MutexDelay@synchronization_internal@absl@@YAHHH@Z
     ?Name@Impl@time_zone@cctz@time_internal@absl@@QBEABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
-    ?Nanoseconds@absl@@YA?AVDuration@1@_J@Z
     ?NegateAndSubtractOne@time_internal@absl@@YA_J_J@Z
     ?Never@KernelTimeout@synchronization_internal@absl@@SA?AV123@XZ
+    ?New@CordRepBtree@cord_internal@absl@@SAPAV123@H@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPAV123@PAUCordRep@23@@Z
+    ?New@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@0@Z
     ?New@CordRepFlat@cord_internal@absl@@SAPAU123@I@Z
     ?New@CordRepRing@cord_internal@absl@@CAPAV123@II@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QAE?AVstring_view@3@XZ
+    ?Next@CordRepBtreeNavigator@cord_internal@absl@@QAEPAUCordRep@23@XZ
+    ?Next@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QBEPAV123@ABVCordzSnapshot@23@@Z
     ?NextCapacity@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@SAII@Z
     ?NextCapacity@?$Storage@PAUCordRep@cord_internal@absl@@$01V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@SAII@Z
@@ -2106,6 +2202,7 @@ EXPORTS
     ?NextTransition@TimeZone@absl@@QBE_NVTime@2@PAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UBE_NABV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PAUcivil_transition@time_zone@234@@Z
     ?NextTransition@TimeZoneLibC@cctz@time_internal@absl@@UBE_NABV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PAUcivil_transition@time_zone@234@@Z
+    ?NextUp@CordRepBtreeNavigator@cord_internal@absl@@AAEPAUCordRep@23@XZ
     ?NominalCPUFrequency@base_internal@absl@@YANXZ
     ?NormalizeLogSeverity@absl@@YA?AW4LogSeverity@1@W421@@Z
     ?NotFoundError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
@@ -2115,6 +2212,7 @@ EXPORTS
     ?Now@UnscaledCycleClockWrapperForGetCurrentTime@time_internal@absl@@SA_JXZ
     ?Now@absl@@YA?AVTime@1@XZ
     ?NumCPUs@base_internal@absl@@YAHXZ
+    ?NumClonedBytes@container_internal@absl@@YAIXZ
     ?ODRCheck@CordzHandle@cord_internal@absl@@ABEXXZ
     ?ODRCheck@CordzInfo@cord_internal@absl@@ABEXXZ
     ?OccursBefore@ViableSubstitution@strings_internal@absl@@QBE_NABU123@@Z
@@ -2150,10 +2248,13 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AAEXXZ
     ?Prepend@Cord@absl@@QAEXABV12@@Z
     ?Prepend@Cord@absl@@QAEXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@II@Z
     ?PrependNode@CordForest@absl@@AAEPAUCordRep@cord_internal@2@PAU342@0@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -2174,6 +2275,8 @@ EXPORTS
     ?Read1To3@MixingHashState@hash_internal@absl@@CAIPBEI@Z
     ?Read4To8@MixingHashState@hash_internal@absl@@CA_KPBEI@Z
     ?Read9To16@MixingHashState@hash_internal@absl@@CA?AU?$pair@_K_K@__1@std@@PBEI@Z
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QAE?AUReadResult@123@II@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@IIAAPAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AAEHPBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AAEHPBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QAEHABUParsedFloat@23@H@Z
@@ -2187,6 +2290,7 @@ EXPORTS
     ?ReclaimThreadIdentity@synchronization_internal@absl@@YAXPAX@Z
     ?RecordInsertSlow@container_internal@absl@@YAXPAUHashtablezInfo@12@II@Z
     ?Ref@CordRep@cord_internal@absl@@SAPAU123@PAU123@@Z
+    ?Ref@Status@absl@@CAXI@Z
     ?RefCordRep@CordzInfo@cord_internal@absl@@QBEPAUCordRep@23@XZ
     ?Register@CycleClockSource@base_internal@absl@@CAXP6A_JXZ@Z
     ?Register@HashtablezSampler@container_internal@absl@@QAEPAUHashtablezInfo@23@XZ
@@ -2214,19 +2318,19 @@ EXPORTS
     ?Reset@?$AllocationTransaction@V?$allocator@PBUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXXZ
     ?Reset@?$AllocationTransaction@V?$allocator@USubRange@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXXZ
-    ?Reset@CordRepRingReader@cord_internal@absl@@QAE?AVstring_view@3@PAVCordRepRing@23@@Z
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AAE_NABV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResetToEmpty@InlineRep@Cord@absl@@AAEXXZ
     ?Resize@?$ResizeUninitializedTraits@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@X@strings_internal@absl@@SAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPAUCordRep@12@V?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@2@@Z
     ?RoundUp@cord_internal@absl@@YAIII@Z
     ?RoundUpForTag@cord_internal@absl@@YAII@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QBE_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPBDI@Z
     ?SampleSlow@container_internal@absl@@YAPAUHashtablezInfo@12@PA_J@Z
-    ?Seconds@absl@@YA?AVDuration@1@_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QAE?AVstring_view@3@I@Z
+    ?Seek@CordRepBtreeNavigator@cord_internal@absl@@QAE?AUPosition@123@I@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@I@Z
     ?SetAllocatedData@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QAEXPAHI@Z
     ?SetAllocatedData@?$Storage@PAUCordRep@cord_internal@absl@@$01V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXPAPAUCordRep@cord_internal@3@I@Z
     ?SetAllocatedData@?$Storage@PAUCordRep@cord_internal@absl@@$0CP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXPAPAUCordRep@cord_internal@3@I@Z
@@ -2263,7 +2367,7 @@ EXPORTS
     ?SetWidth@FormatConversionSpecImplFriend@str_format_internal@absl@@SAXHPAVFormatConversionSpecImpl@23@@Z
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QAEXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QAEXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_NIPAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_NIPBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QAEXXZ
     ?SignalAll@CondVar@absl@@QAEXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PA_N@Z
@@ -2273,6 +2377,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SAIXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SAIXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SAIXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QAE?AUPosition@123@I@Z
     ?SleepFor@absl@@YAXVDuration@1@@Z
     ?SlowLock@SpinLock@base_internal@absl@@AAEXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AAEXI@Z
@@ -2303,6 +2408,7 @@ EXPORTS
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@ABVAlphaNum@1@000@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@ABVAlphaNum@1@00@Z
     ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@ABVAlphaNum@1@0@Z
+    ?StrCat@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@ABVAlphaNum@1@@Z
     ?StrReplaceAll@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@1@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@4@@Z
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?StripAsciiWhitespace@absl@@YA?AVstring_view@1@V21@@Z
@@ -2311,6 +2417,7 @@ EXPORTS
     ?StrlenInternal@string_view@absl@@CAIPBD@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AAEXII@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@III@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QAEPAUCordRep@23@II@Z
     ?Subcord@Cord@absl@@QBE?AV12@II@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PBV62@I@Z
     ?SubtractSize@?$Storage@H$0CP@V?$allocator@H@__1@std@@@inlined_vector_internal@absl@@QAEXI@Z
@@ -2380,6 +2487,7 @@ EXPORTS
     ?ToInt64Minutes@absl@@YA_JVDuration@1@@Z
     ?ToInt64Nanoseconds@absl@@YA_JVDuration@1@@Z
     ?ToInt64Seconds@absl@@YA_JVDuration@1@@Z
+    ?ToOpResult@CordRepBtree@cord_internal@absl@@AAE?AUOpResult@123@_N@Z
     ?ToString@?$BigUnsigned@$03@strings_internal@absl@@QBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@?$BigUnsigned@$0FE@@strings_internal@absl@@QBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?ToString@Status@absl@@QBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4StatusToStringMode@2@@Z
@@ -2816,6 +2924,7 @@ EXPORTS
     ?back@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEAAUTransition@cctz@time_internal@absl@@XZ
     ?back@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEAAUTransitionType@cctz@time_internal@absl@@XZ
     ?back@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QAEAAUViableSubstitution@strings_internal@absl@@XZ
+    ?back@CordRepBtree@cord_internal@absl@@QBEIXZ
     ?base@?$__wrap_iter@PAPAVCordzHandle@cord_internal@absl@@@__1@std@@QBEPAPAVCordzHandle@cord_internal@absl@@XZ
     ?base@?$__wrap_iter@PAUTransition@cctz@time_internal@absl@@@__1@std@@QBEPAUTransition@cctz@time_internal@absl@@XZ
     ?base@?$__wrap_iter@PAUTransitionType@cctz@time_internal@absl@@@__1@std@@QBEPAUTransitionType@cctz@time_internal@absl@@XZ
@@ -2829,6 +2938,7 @@ EXPORTS
     ?begin@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QAEPAUPayload@status_internal@2@XZ
     ?begin@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QBEPBUPayload@status_internal@2@XZ
     ?begin@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QBEPBVFormatArgImpl@str_format_internal@2@XZ
+    ?begin@?$Span@QAUCordRep@cord_internal@absl@@@absl@@QBEPBQAUCordRep@cord_internal@2@XZ
     ?begin@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAE?AV?$__hash_iterator@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@23@XZ
     ?begin@?$__split_buffer@PAPBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEPAPAPBVImpl@time_zone@cctz@time_internal@absl@@XZ
     ?begin@?$initializer_list@PAUCordRep@cord_internal@absl@@@std@@QBEPBQAUCordRep@cord_internal@absl@@XZ
@@ -2842,8 +2952,13 @@ EXPORTS
     ?begin@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE?AV?$__wrap_iter@PAUTransition@cctz@time_internal@absl@@@23@XZ
     ?begin@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE?AV?$__wrap_iter@PAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?begin@ChunkRange@Cord@absl@@QBE?AVChunkIterator@23@XZ
+    ?begin@CordRepBtree@cord_internal@absl@@QBEIXZ
     ?begin@Storage@?$FixedArray@PAUCordRep@cord_internal@absl@@$0PPPPPPPP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QBEPAPAUCordRep@cord_internal@3@XZ
     ?begin@string_view@absl@@QBEPBDXZ
+    ?btree@CordRep@cord_internal@absl@@QAEPAVCordRepBtree@23@XZ
+    ?btree@CordRep@cord_internal@absl@@QBEPBVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeNavigator@cord_internal@absl@@QBEPAVCordRepBtree@23@XZ
+    ?btree@CordRepBtreeReader@cord_internal@absl@@QBEPAVCordRepBtree@23@XZ
     ?bucket_count@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QBEIXZ
     ?capacity@?$__split_buffer@PAPBVImpl@time_zone@cctz@time_internal@absl@@AAV?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
     ?capacity@?$__split_buffer@PAPBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
@@ -2870,6 +2985,7 @@ EXPORTS
     ?capacity@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
     ?capacity@?$vector@UViableSubstitution@strings_internal@absl@@V?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
     ?capacity@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
+    ?capacity@CordRepBtree@cord_internal@absl@@QBEIXZ
     ?capacity@CordRepRing@cord_internal@absl@@QBEIXZ
     ?chunk_begin@Cord@absl@@QBE?AVChunkIterator@12@XZ
     ?chunk_end@Cord@absl@@QBE?AVChunkIterator@12@XZ
@@ -2898,9 +3014,9 @@ EXPORTS
     ?compare_exchange_weak@?$__atomic_base@PAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QAE_NAAPAUHashtablezInfo@container_internal@absl@@PAU456@W4memory_order@23@2@Z
     ?concat@CordRep@cord_internal@absl@@QAEPAUCordRepConcat@23@XZ
     ?concat@CordRep@cord_internal@absl@@QBEPBUCordRepConcat@23@XZ
-    ?consumed@CordRepRingReader@cord_internal@absl@@QBEIXZ
+    ?consumed@CordRepBtreeReader@cord_internal@absl@@QBEIXZ
     ?conversion_char@FormatConversionSpecImpl@str_format_internal@absl@@QBE?AW4FormatConversionChar@3@XZ
-    ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cordz_info@InlineData@cord_internal@absl@@QBEPAVCordzInfo@23@XZ
     ?cordz_info@InlineRep@Cord@absl@@QBEPAVCordzInfo@cord_internal@3@XZ
     ?cordz_should_profile@cord_internal@absl@@YA_NXZ
@@ -2916,6 +3032,7 @@ EXPORTS
     ?data@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QBEPBVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$Span@D@absl@@QBEPADXZ
     ?data@?$Span@I@absl@@QBEPAIXZ
+    ?data@?$Span@QAUCordRep@cord_internal@absl@@@absl@@QBEPBQAUCordRep@cord_internal@2@XZ
     ?data@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QBEPAVFormatArgImpl@str_format_internal@2@XZ
     ?data@?$vector@PAUCordRep@cord_internal@absl@@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@__1@std@@QBEPBQAUCordRep@cord_internal@absl@@XZ
     ?data@?$vector@PAVCordzHandle@cord_internal@absl@@V?$allocator@PAVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@QBEPBQAVCordzHandle@cord_internal@absl@@XZ
@@ -3008,6 +3125,7 @@ EXPORTS
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QAEPAUPayload@status_internal@2@XZ
     ?end@?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@QBEPBUPayload@status_internal@2@XZ
     ?end@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QBEPBVFormatArgImpl@str_format_internal@2@XZ
+    ?end@?$Span@QAUCordRep@cord_internal@absl@@@absl@@QBEPBQAUCordRep@cord_internal@2@XZ
     ?end@?$__deque_base@PBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@IAE?AV?$__deque_iterator@PBVImpl@time_zone@cctz@time_internal@absl@@PAPBV12345@AAPBV12345@PAPAPBV12345@H$0A@@23@XZ
     ?end@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAE?AV?$__hash_iterator@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@23@XZ
     ?end@?$__split_buffer@PAPBVImpl@time_zone@cctz@time_internal@absl@@V?$allocator@PAPBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEPAPAPBVImpl@time_zone@cctz@time_internal@absl@@XZ
@@ -3020,6 +3138,7 @@ EXPORTS
     ?end@?$vector@UTransition@cctz@time_internal@absl@@V?$allocator@UTransition@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE?AV?$__wrap_iter@PAUTransition@cctz@time_internal@absl@@@23@XZ
     ?end@?$vector@UTransitionType@cctz@time_internal@absl@@V?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE?AV?$__wrap_iter@PAUTransitionType@cctz@time_internal@absl@@@23@XZ
     ?end@ChunkRange@Cord@absl@@QBE?AVChunkIterator@23@XZ
+    ?end@CordRepBtree@cord_internal@absl@@QBEIXZ
     ?end@Storage@?$FixedArray@PAUCordRep@cord_internal@absl@@$0PPPPPPPP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QBEPAPAUCordRep@cord_internal@3@XZ
     ?end@string_view@absl@@QBEPBDXZ
     ?entries@CordRepRing@cord_internal@absl@@QBEIII@Z
@@ -3027,7 +3146,6 @@ EXPORTS
     ?entry_begin_pos@CordRepRing@cord_internal@absl@@QBEABII@Z
     ?entry_child@CordRepRing@cord_internal@absl@@AAEPAPAUCordRep@23@XZ
     ?entry_child@CordRepRing@cord_internal@absl@@QBEABQAUCordRep@23@I@Z
-    ?entry_data@CordRepRing@cord_internal@absl@@QBE?AVstring_view@3@I@Z
     ?entry_data_offset@CordRepRing@cord_internal@absl@@AAEPAIXZ
     ?entry_data_offset@CordRepRing@cord_internal@absl@@QBEABII@Z
     ?entry_end_offset@CordRepRing@cord_internal@absl@@QBEII@Z
@@ -3040,6 +3158,7 @@ EXPORTS
     ?exchange@?$__atomic_base@P6AXABUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QAEP6AXABUHashtablezInfo@container_internal@absl@@@ZP6AX0@ZW4memory_order@23@@Z
     ?external@CordRep@cord_internal@absl@@QAEPAUCordRepExternal@23@XZ
     ?external@CordRep@cord_internal@absl@@QBEPBUCordRepExternal@23@XZ
+    ?fetch_add_end@CordRepBtree@cord_internal@absl@@AAEII@Z
     ?find@?$unordered_map@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAE?AV?$__hash_map_iterator@V?$__hash_iterator@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@23@ABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@23@@Z
     ?find@string_view@absl@@QBEIDI@Z
     ?find@string_view@absl@@QBEIV12@I@Z
@@ -3161,9 +3280,11 @@ EXPORTS
     ?hash_function@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAEAAV?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@XZ
     ?head@CordRepRing@cord_internal@absl@@QBEIXZ
     ?head@Filler@CordRepRing@cord_internal@absl@@QBEIXZ
+    ?height@CordRepBtree@cord_internal@absl@@QBEHXZ
     ?hour@?$civil_time@Uhour_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QBEHXZ
     ?hour@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QBEHXZ
     ?hour@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QBEHXZ
+    ?index@CordRepBtree@cord_internal@absl@@QBEIW4EdgeType@123@@Z
     ?inline_size@InlineData@cord_internal@absl@@QBEIXZ
     ?inline_size@InlineRep@Cord@absl@@ABEIXZ
     ?is_basic@FormatConversionSpecImpl@str_format_internal@absl@@QBE_NXZ
@@ -3180,7 +3301,7 @@ EXPORTS
     ?is_tree@InlineRep@Cord@absl@@QBE_NXZ
     ?key_eq@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAEAAV?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@XZ
     ?length@?$Span@D@absl@@QBEIXZ
-    ?length@CordRepRingReader@cord_internal@absl@@QBEIXZ
+    ?length@CordRepBtreeReader@cord_internal@absl@@QBEIXZ
     ?length@string_view@absl@@QBEIXZ
     ?load@?$__atomic_base@P6AXABUHashtablezInfo@container_internal@absl@@@Z$0A@@__1@std@@QBEP6AXABUHashtablezInfo@container_internal@absl@@@ZW4memory_order@23@@Z
     ?load@?$__atomic_base@PAUHashtablezInfo@container_internal@absl@@$0A@@__1@std@@QBEPAUHashtablezInfo@container_internal@absl@@W4memory_order@23@@Z
@@ -3295,7 +3416,6 @@ EXPORTS
     ?release@?$unique_ptr@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@23@@__1@std@@QAEPAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@23@XZ
     ?release@?$unique_ptr@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@U?$default_delete@V?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@@__1@std@@@__1@std@@QAEPAV?$InlinedVector@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@absl@@XZ
     ?release@?$unique_ptr@VTimeZoneInfo@cctz@time_internal@absl@@U?$default_delete@VTimeZoneInfo@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAEPAVTimeZoneInfo@cctz@time_internal@absl@@XZ
-    ?remaining@CordRepRingReader@cord_internal@absl@@QBEIXZ
     ?remove_prefix@InlineRep@Cord@absl@@QAEXI@Z
     ?remove_prefix@string_view@absl@@QAEXI@Z
     ?remove_suffix@string_view@absl@@QAEXI@Z
@@ -3319,7 +3439,6 @@ EXPORTS
     ?rfind@string_view@absl@@QBEIV12@I@Z
     ?ring@CordRep@cord_internal@absl@@QAEPAVCordRepRing@23@XZ
     ?ring@CordRep@cord_internal@absl@@QBEPBVCordRepRing@23@XZ
-    ?ring@CordRepRingReader@cord_internal@absl@@QBEPAVCordRepRing@23@XZ
     ?safe_strto128_base@numbers_internal@absl@@YA_NVstring_view@2@PAVint128@2@H@Z
     ?safe_strto32_base@numbers_internal@absl@@YA_NVstring_view@2@PAHH@Z
     ?safe_strto64_base@numbers_internal@absl@@YA_NVstring_view@2@PA_JH@Z
@@ -3370,11 +3489,13 @@ EXPORTS
     ?second@?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@detail@cctz@time_internal@absl@@QBEHXZ
     ?second@?$civil_time@Usecond_tag@time_internal@absl@@@detail@cctz@time_internal@absl@@QBEHXZ
     ?set_arg@BoundConversion@str_format_internal@absl@@QAEXPBVFormatArgImpl@23@@Z
+    ?set_begin@CordRepBtree@cord_internal@absl@@AAEXI@Z
     ?set_cordz_info@InlineData@cord_internal@absl@@QAEXPAVCordzInfo@23@@Z
     ?set_cordz_mean_interval@cord_internal@absl@@YAXH@Z
     ?set_data@InlineRep@Cord@absl@@QAEPADI@Z
     ?set_data@InlineRep@Cord@absl@@QAEXPBDI_N@Z
     ?set_depth@CordRepConcat@cord_internal@absl@@QAEXE@Z
+    ?set_end@CordRepBtree@cord_internal@absl@@AAEXI@Z
     ?set_from_arg@InputValue@UnboundConversion@str_format_internal@absl@@QAEXH@Z
     ?set_inline_size@InlineData@cord_internal@absl@@QAEXI@Z
     ?set_inline_size@InlineRep@Cord@absl@@AAEXI@Z
@@ -3393,6 +3514,7 @@ EXPORTS
     ?size@?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@absl@@QBEIXZ
     ?size@?$Span@D@absl@@QBEIXZ
     ?size@?$Span@I@absl@@QBEIXZ
+    ?size@?$Span@QAUCordRep@cord_internal@absl@@@absl@@QBEIXZ
     ?size@?$Span@VFormatArgImpl@str_format_internal@absl@@@absl@@QBEIXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PAU?$__hash_node_base@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QAEAAIXZ
     ?size@?$__bucket_list_deallocator@V?$allocator@PAU?$__hash_node_base@PAU?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@__1@std@@@__1@std@@QBEIXZ
@@ -3414,6 +3536,7 @@ EXPORTS
     ?size@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@QBEIXZ
     ?size@AlphaNum@absl@@QBEIXZ
     ?size@Cord@absl@@QBEIXZ
+    ?size@CordRepBtree@cord_internal@absl@@QBEIXZ
     ?size@InlineRep@Cord@absl@@QBEIXZ
     ?size@Storage@?$FixedArray@PAUCordRep@cord_internal@absl@@$0PPPPPPPP@V?$allocator@PAUCordRep@cord_internal@absl@@@__1@std@@@absl@@QBEIXZ
     ?size@string_view@absl@@QBEIXZ
@@ -3425,6 +3548,7 @@ EXPORTS
     ?store@?$__atomic_base@W4OnDeadlockCycle@absl@@$0A@@__1@std@@QAEXW4OnDeadlockCycle@absl@@W4memory_order@23@@Z
     ?store@?$__atomic_base@W4State@PerThreadSynch@base_internal@absl@@$0A@@__1@std@@QAEXW4State@PerThreadSynch@base_internal@absl@@W4memory_order@23@@Z
     ?str@UntypedFormatSpecImpl@str_format_internal@absl@@QBE?AVstring_view@3@XZ
+    ?sub_fetch_begin@CordRepBtree@cord_internal@absl@@AAEII@Z
     ?substr@string_view@absl@@QBE?AV12@II@Z
     ?substring@CordRep@cord_internal@absl@@QAEPAUCordRepSubstring@23@XZ
     ?substring@CordRep@cord_internal@absl@@QBEPBUCordRepSubstring@23@XZ
diff --git a/chromium/third_party/abseil-cpp/symbols_x86_rel.def b/chromium/third_party/abseil-cpp/symbols_x86_rel.def
index ab55f2e0b2c..4cadd321169 100644
--- a/chromium/third_party/abseil-cpp/symbols_x86_rel.def
+++ b/chromium/third_party/abseil-cpp/symbols_x86_rel.def
@@ -3,6 +3,12 @@ EXPORTS
     ??$?0V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QAE@$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$?MUsecond_tag@detail@cctz@time_internal@absl@@U01234@@detail@cctz@time_internal@absl@@YA_NABV?$civil_time@Usecond_tag@detail@cctz@time_internal@absl@@@0123@0@Z
     ??$?RW4LogSeverity@absl@@ABQBDHAAPBD@?$AtomicHook@P6AXW4LogSeverity@absl@@PBDHABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z@base_internal@absl@@QBEX$$QAW4LogSeverity@2@ABQBD$$QAHAAPBD@Z
+    ??$AddCordRep@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@PAUCordRep@12@@Z
+    ??$AddCordRep@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@PAUCordRep@12@@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@AAE?AVstring_view@2@V32@I@Z
+    ??$AddData@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@Vstring_view@2@I@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@AAE?AVstring_view@2@V32@I@Z
+    ??$AddData@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@Vstring_view@2@I@Z
     ??$AddRing@$00@CordRepRing@cord_internal@absl@@CAPAV012@PAV012@0II@Z
     ??$AddRing@$0A@@CordRepRing@cord_internal@absl@@CAPAV012@PAV012@0II@Z
     ??$Append@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QAEX$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
@@ -62,12 +68,18 @@ EXPORTS
     ??$GenericCompare@HVstring_view@absl@@@absl@@YAHABVCord@0@ABVstring_view@0@I@Z
     ??$GenericCompare@_NVCord@absl@@@absl@@YA_NABVCord@0@0I@Z
     ??$GenericCompare@_NVstring_view@absl@@@absl@@YA_NABVCord@0@ABVstring_view@0@I@Z
+    ??$Merge@$00@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@0@Z
+    ??$Merge@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@PAV012@0@Z
+    ??$NewLeaf@$00@CordRepBtree@cord_internal@absl@@CAPAV012@Vstring_view@2@I@Z
+    ??$NewLeaf@$0A@@CordRepBtree@cord_internal@absl@@CAPAV012@Vstring_view@2@I@Z
     ??$ParseFloat@$09@strings_internal@absl@@YA?AUParsedFloat@01@PBD0W4chars_format@1@@Z
     ??$ParseFloat@$0BA@@strings_internal@absl@@YA?AUParsedFloat@01@PBD0W4chars_format@1@@Z
     ??$ParseFormatString@UParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@@str_format_internal@absl@@YA_NVstring_view@1@UParsedFormatConsumer@ParsedFormatBase@01@@Z
     ??$Prepend@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@Cord@absl@@QAEX$$QAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ??$STLStringReserveAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
     ??$STLStringResizeUninitializedAmortized@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@I@Z
+    ??$SetEdge@$00@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
+    ??$SetEdge@$0A@@CordRepBtree@cord_internal@absl@@QAE?AUOpResult@012@_NPAUCordRep@12@I@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@0@ABV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@3@@Z
     ??$StrReplaceAll@V?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@@absl@@YAHABV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@2@@Z
     ??$__construct_node_hash@ABUpiecewise_construct_t@__1@std@@V?$tuple@ABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@V?$tuple@$$V@23@@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@AAE?AV?$unique_ptr@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@V?$__hash_node_destructor@V?$allocator@U?$__hash_node@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@PAX@__1@std@@@__1@std@@@23@@12@IABUpiecewise_construct_t@12@$$QAV?$tuple@ABV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@12@$$QAV?$tuple@$$V@12@@Z
@@ -94,13 +106,14 @@ EXPORTS
     ??0?$__split_buffer@UTransitionType@cctz@time_internal@absl@@AAV?$allocator@UTransitionType@cctz@time_internal@absl@@@__1@std@@@__1@std@@QAE@IIAAV?$allocator@UTransitionType@cctz@time_internal@absl@@@12@@Z
     ??0?$__split_buffer@UViableSubstitution@strings_internal@absl@@AAV?$allocator@UViableSubstitution@strings_internal@absl@@@__1@std@@@__1@std@@QAE@IIAAV?$allocator@UViableSubstitution@strings_internal@absl@@@12@@Z
     ??0AlphaNum@absl@@QAE@I@Z
-    ??0AlphaNum@absl@@QAE@PBD@Z
     ??0AlphaNum@absl@@QAE@UDec@1@@Z
     ??0AlphaNum@absl@@QAE@UHex@1@@Z
     ??0Arena@LowLevelAlloc@base_internal@absl@@QAE@I@Z
     ??0Arg@substitute_internal@absl@@QAE@PBX@Z
     ??0Arg@substitute_internal@absl@@QAE@UDec@2@@Z
     ??0Arg@substitute_internal@absl@@QAE@UHex@2@@Z
+    ??0BadStatusOrAccess@absl@@QAE@$$QAV01@@Z
+    ??0BadStatusOrAccess@absl@@QAE@ABV01@@Z
     ??0BadStatusOrAccess@absl@@QAE@VStatus@1@@Z
     ??0BlockingCounter@absl@@QAE@H@Z
     ??0ByAnyChar@absl@@QAE@Vstring_view@1@@Z
@@ -145,6 +158,8 @@ EXPORTS
     ??1bad_optional_access@absl@@UAE@XZ
     ??1bad_variant_access@absl@@UAE@XZ
     ??4?$optional_data@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@$0A@@optional_internal@absl@@IAEAAV012@$$QAV012@@Z
+    ??4BadStatusOrAccess@absl@@QAEAAV01@$$QAV01@@Z
+    ??4BadStatusOrAccess@absl@@QAEAAV01@ABV01@@Z
     ??4Cord@absl@@QAEAAV01@Vstring_view@1@@Z
     ??6absl@@YAAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AAV123@ABVCord@0@@Z
     ??6absl@@YAAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@AAV123@ABVStatus@0@@Z
@@ -176,6 +191,7 @@ EXPORTS
     ??Kabsl@@YA?AVuint128@0@V10@0@Z
     ??Labsl@@YA?AVint128@0@V10@0@Z
     ??Labsl@@YA?AVuint128@0@V10@0@Z
+    ??R<lambda_1>@?0??CompareSlowPath@Cord@absl@@ABEHABV23@II@Z@QBE?A?<auto>@@PAVChunkIterator@23@PAVstring_view@3@@Z
     ??R?$default_delete@$$CBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@QBEXPBVImpl@time_zone@cctz@time_internal@absl@@@Z
     ??XDuration@absl@@QAEAAV01@N@Z
     ??XDuration@absl@@QAEAAV01@_J@Z
@@ -197,7 +213,7 @@ EXPORTS
     ?AddWithCarry@?$BigUnsigned@$0FE@@strings_internal@absl@@AAEXH_K@Z
     ?AddressIsReadable@debugging_internal@absl@@YA_NPBX@Z
     ?AdvanceAndReadBytes@ChunkIterator@Cord@absl@@AAE?AV23@I@Z
-    ?AdvanceBytesRing@ChunkIterator@Cord@absl@@AAEXI@Z
+    ?AdvanceBytesBtree@ChunkIterator@Cord@absl@@AAEXI@Z
     ?AdvanceBytesSlowPath@ChunkIterator@Cord@absl@@AAEXI@Z
     ?AdvanceStack@ChunkIterator@Cord@absl@@AAEAAV123@XZ
     ?Alloc@LowLevelAlloc@base_internal@absl@@SAPAXI@Z
@@ -205,6 +221,7 @@ EXPORTS
     ?AlreadyExistsError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Append@Cord@absl@@QAEX$$QAV12@@Z
     ?Append@Cord@absl@@QAEXABV12@@Z
+    ?Append@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
     ?Append@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Append@FormatSinkImpl@str_format_internal@absl@@QAEXID@Z
@@ -214,6 +231,7 @@ EXPORTS
     ?AppendLeaf@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@II@Z
     ?AppendPack@str_format_internal@absl@@YAAAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PAV345@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
     ?AppendPieces@strings_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@V?$initializer_list@Vstring_view@absl@@@5@@Z
+    ?AppendSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?AppendSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?AppendTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?AppendTreeToInlined@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -270,20 +288,24 @@ EXPORTS
     ?CompareSlowPath@Cord@absl@@ABEHABV12@II@Z
     ?CompareSlowPath@Cord@absl@@ABEHVstring_view@2@II@Z
     ?ConcatNodes@CordForest@absl@@QAEPAUCordRep@cord_internal@2@XZ
+    ?Consume@cord_internal@absl@@YAXPAUCordRep@12@V?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@2@@Z
     ?ConsumeUnboundConversion@str_format_internal@absl@@YAPBDPBD0PAUUnboundConversion@12@PAH@Z
     ?ConvertDateTime@absl@@YA?AUTimeConversion@1@_JHHHHHVTimeZone@1@@Z
-    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPACI@Z
+    ?ConvertDeletedToEmptyAndFullToDeleted@container_internal@absl@@YAXPAW4ctrl_t@12@I@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NMABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NNABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertFloatImpl@str_format_internal@absl@@YA_NOABVFormatConversionSpecImpl@12@PAVFormatSinkImpl@12@@Z
     ?ConvertOne@ParsedFormatConsumer@ParsedFormatBase@str_format_internal@absl@@QAE_NABUUnboundConversion@34@Vstring_view@4@@Z
     ?Copy@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@III@Z
     ?CopyCordToString@absl@@YAXABVCord@1@PAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
+    ?CopyPrefix@CordRepBtree@cord_internal@absl@@AAE?AUCopyResult@123@I@Z
+    ?CopySuffix@CordRepBtree@cord_internal@absl@@AAE?AUCopyResult@123@I@Z
     ?CopyTo@InlineRep@Cord@absl@@QBEXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@Z
     ?CopyToArraySlowPath@Cord@absl@@ABEXPAD@Z
     ?Crash@Helper@internal_statusor@absl@@SAXABVStatus@3@@Z
     ?Create@CordRepRing@cord_internal@absl@@SAPAV123@PAUCordRep@23@I@Z
     ?CreateFromLeaf@CordRepRing@cord_internal@absl@@CAPAV123@PAUCordRep@23@III@Z
+    ?CreateSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAUCordRep@23@@Z
     ?CreateSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAUCordRep@23@I@Z
     ?CreateThreadIdentity@synchronization_internal@absl@@YAPAUThreadIdentity@base_internal@2@XZ
     ?CurrentThreadIdentityIfPresent@base_internal@absl@@YAPAUThreadIdentity@12@XZ
@@ -306,6 +328,8 @@ EXPORTS
     ?Destroy@PerThreadSem@synchronization_internal@absl@@CAXPAUThreadIdentity@base_internal@3@@Z
     ?DestroyContents@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@AAEXXZ
     ?DestroyCordSlow@Cord@absl@@AAEXXZ
+    ?DestroyLeaf@CordRepBtree@cord_internal@absl@@CAXPAV123@II@Z
+    ?DestroyNonLeaf@CordRepBtree@cord_internal@absl@@CAXPAV123@II@Z
     ?DiagnosticsGetDeleteQueue@CordzHandle@cord_internal@absl@@SA?AV?$vector@PBVCordzHandle@cord_internal@absl@@V?$allocator@PBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsGetSafeToInspectDeletedHandles@CordzHandle@cord_internal@absl@@QAE?AV?$vector@PBVCordzHandle@cord_internal@absl@@V?$allocator@PBVCordzHandle@cord_internal@absl@@@__1@std@@@__1@std@@XZ
     ?DiagnosticsHandleIsSafeToInspect@CordzHandle@cord_internal@absl@@QBE_NPBV123@@Z
@@ -318,6 +342,9 @@ EXPORTS
     ?DummyFunction@?$AtomicHook@P6AXPBX_J@Z@base_internal@absl@@CAXPBX_J@Z
     ?DummyFunction@?$AtomicHook@P6AX_J@Z@base_internal@absl@@CAX_J@Z
     ?DummyFunction@?$AtomicHook@P6A_NW4LogSeverity@absl@@PBDHPAPADPAH@Z@base_internal@absl@@CA_NW4LogSeverity@3@PBDHPAPADPAH@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@AAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@Vstring_view@3@AAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
+    ?Dump@CordRepBtree@cord_internal@absl@@SAXPBUCordRep@23@Vstring_view@3@_NAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?DumpPCAndFrameSizesAndStackTrace@debugging_internal@absl@@YAXPAXQBQAXQAHHH_NP6AXPBD0@Z0@Z
     ?DurationFromTimespec@absl@@YA?AVDuration@1@Utimespec@@@Z
     ?DurationFromTimeval@absl@@YA?AVDuration@1@Utimeval@@@Z
@@ -411,8 +438,11 @@ EXPORTS
     ?FromUDate@absl@@YA?AVTime@1@N@Z
     ?FromUniversal@absl@@YA?AVTime@1@_J@Z
     ?FromUnixSeconds@cctz@time_internal@absl@@YA?AV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@_J@Z
+    ?GetAppendBuffer@CordRepBtree@cord_internal@absl@@QAE?AV?$Span@D@3@I@Z
     ?GetAppendBuffer@CordRepRing@cord_internal@absl@@QAE?AV?$Span@D@3@I@Z
+    ?GetAppendBufferSlow@CordRepBtree@cord_internal@absl@@AAE?AV?$Span@D@3@I@Z
     ?GetCachedTID@base_internal@absl@@YAIXZ
+    ?GetCharacter@CordRepBtree@cord_internal@absl@@QBEDI@Z
     ?GetCharacter@CordRepRing@cord_internal@absl@@QBEDI@Z
     ?GetCordzStatistics@CordzInfo@cord_internal@absl@@QBE?AUCordzStatistics@23@XZ
     ?GetCurrentTimeNanos@absl@@YA_JXZ
@@ -452,6 +482,7 @@ EXPORTS
     ?Init@PerThreadSem@synchronization_internal@absl@@CAXPAUThreadIdentity@base_internal@3@@Z
     ?InitFrom@?$Storage@UPayload@status_internal@absl@@$00V?$allocator@UPayload@status_internal@absl@@@__1@std@@@inlined_vector_internal@absl@@QAEXABV123@@Z
     ?InitTree@ChunkIterator@Cord@absl@@AAEXPAUCordRep@cord_internal@3@@Z
+    ?InitWhat@BadStatusOrAccess@absl@@ABEXXZ
     ?Initialize@ExponentialBiased@base_internal@absl@@AAEXXZ
     ?InitializeCordRepExternal@cord_internal@absl@@YAXVstring_view@2@PAUCordRepExternal@12@@Z
     ?InitializeSymbolizer@absl@@YAXPBD@Z
@@ -467,6 +498,8 @@ EXPORTS
     ?IsDataLoss@absl@@YA_NABVStatus@1@@Z
     ?IsDeadlineExceeded@absl@@YA_NABVStatus@1@@Z
     ?IsFailedPrecondition@absl@@YA_NABVStatus@1@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QBE_NIIPAVstring_view@3@@Z
+    ?IsFlat@CordRepBtree@cord_internal@absl@@QBE_NPAVstring_view@3@@Z
     ?IsInternal@absl@@YA_NABVStatus@1@@Z
     ?IsInvalidArgument@absl@@YA_NABVStatus@1@@Z
     ?IsNotFound@absl@@YA_NABVStatus@1@@Z
@@ -478,6 +511,7 @@ EXPORTS
     ?IsUnavailable@absl@@YA_NABVStatus@1@@Z
     ?IsUnimplemented@absl@@YA_NABVStatus@1@@Z
     ?IsUnknown@absl@@YA_NABVStatus@1@@Z
+    ?IsValid@CordRepBtree@cord_internal@absl@@SA_NPBV123@_N@Z
     ?IsValid@CordRepRing@cord_internal@absl@@QBE_NAAV?$basic_ostream@DU?$char_traits@D@__1@std@@@__1@std@@@Z
     ?Iterate@HashtablezSampler@container_internal@absl@@QAE_JABV?$function@$$A6AXABUHashtablezInfo@container_internal@absl@@@Z@__1@std@@@Z
     ?LengthModToString@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@W4LengthMod@12@@Z
@@ -504,6 +538,7 @@ EXPORTS
     ?MaxFlatLength@CordTestAccess@strings_internal@absl@@SAIXZ
     ?MaybeTrackCordImpl@CordzInfo@cord_internal@absl@@CAXAAVInlineData@23@ABV423@W4MethodIdentifier@CordzUpdateTracker@23@@Z
     ?MemoryUsageAux@Cord@absl@@CAIPBUCordRep@cord_internal@2@@Z
+    ?MergeTrees@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@0@Z
     ?MovedFromString@Status@absl@@CAPBV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@AAEXHPBI@Z
     ?MultiplyBy@?$BigUnsigned@$03@strings_internal@absl@@QAEXI@Z
@@ -522,7 +557,6 @@ EXPORTS
     ?New@CordRepFlat@cord_internal@absl@@SAPAU123@I@Z
     ?New@CordRepRing@cord_internal@absl@@CAPAV123@II@Z
     ?NewArena@LowLevelAlloc@base_internal@absl@@SAPAUArena@123@H@Z
-    ?Next@CordRepRingReader@cord_internal@absl@@QAE?AVstring_view@3@XZ
     ?Next@CordzInfo@cord_internal@absl@@QBEPAV123@ABVCordzSnapshot@23@@Z
     ?NextTransition@TimeZone@absl@@QBE_NVTime@2@PAUCivilTransition@12@@Z
     ?NextTransition@TimeZoneInfo@cctz@time_internal@absl@@UBE_NABV?$time_point@Vsystem_clock@chrono@__1@std@@V?$duration@_JV?$ratio@$00$00@__1@std@@@234@@chrono@__1@std@@PAUcivil_transition@time_zone@234@@Z
@@ -561,9 +595,11 @@ EXPORTS
     ?PrepareToModify@Status@absl@@AAEXXZ
     ?Prepend@Cord@absl@@QAEXABV12@@Z
     ?Prepend@Cord@absl@@QAEXVstring_view@2@@Z
+    ?Prepend@CordRepBtree@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@PAUCordRep@23@@Z
     ?Prepend@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@Vstring_view@3@I@Z
     ?PrependLeaf@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@II@Z
+    ?PrependSlow@CordRepBtree@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?PrependSlow@CordRepRing@cord_internal@absl@@CAPAV123@PAV123@PAUCordRep@23@@Z
     ?PrependTree@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
     ?PrependTreeToInlined@InlineRep@Cord@absl@@QAEXPAUCordRep@cord_internal@3@W4MethodIdentifier@CordzUpdateTracker@53@@Z
@@ -578,6 +614,8 @@ EXPORTS
     ?PutPaddedString@FormatSinkImpl@str_format_internal@absl@@QAE_NVstring_view@3@HH_N@Z
     ?RawLog@raw_logging_internal@absl@@YAXW4LogSeverity@2@PBDH1ZZ
     ?RawLoggingFullySupported@raw_logging_internal@absl@@YA_NXZ
+    ?Read@CordRepBtreeNavigator@cord_internal@absl@@QAE?AUReadResult@123@II@Z
+    ?Read@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@IIAAPAUCordRep@23@@Z
     ?ReadDigits@?$BigUnsigned@$03@strings_internal@absl@@AAEHPBD0H@Z
     ?ReadDigits@?$BigUnsigned@$0FE@@strings_internal@absl@@AAEHPBD0H@Z
     ?ReadFloatMantissa@?$BigUnsigned@$03@strings_internal@absl@@QAEHABUParsedFloat@23@H@Z
@@ -612,10 +650,11 @@ EXPORTS
     ?ResetToBuiltinUTC@TimeZoneInfo@cctz@time_internal@absl@@AAE_NABV?$duration@_JV?$ratio@$00$00@__1@std@@@chrono@__1@std@@@Z
     ?ResourceExhaustedError@absl@@YA?AVStatus@1@Vstring_view@1@@Z
     ?Rethrow@variant_internal@absl@@YAXXZ
+    ?ReverseConsume@cord_internal@absl@@YAXPAUCordRep@12@V?$FunctionRef@$$A6AXPAUCordRep@cord_internal@absl@@II@Z@2@@Z
     ?SafeToDelete@CordzHandle@cord_internal@absl@@QBE_NXZ
     ?SafeWriteToStderr@raw_logging_internal@absl@@YAXPBDI@Z
     ?SampleSlow@container_internal@absl@@YAPAUHashtablezInfo@12@PA_J@Z
-    ?Seek@CordRepRingReader@cord_internal@absl@@QAE?AVstring_view@3@I@Z
+    ?Seek@CordRepBtreeReader@cord_internal@absl@@QAE?AVstring_view@3@I@Z
     ?SetCapacityForTesting@CordRepRing@cord_internal@absl@@QAEXI@Z
     ?SetCurrentThreadIdentity@base_internal@absl@@YAXPAUThreadIdentity@12@P6AXPAX@Z@Z
     ?SetDisposeCallback@HashtablezSampler@container_internal@absl@@QAEP6AXABUHashtablezInfo@23@@ZP6AX0@Z@Z
@@ -631,7 +670,7 @@ EXPORTS
     ?SetToZero@?$BigUnsigned@$0FE@@strings_internal@absl@@QAEXXZ
     ?ShiftLeft@?$BigUnsigned@$03@strings_internal@absl@@QAEXH@Z
     ?ShiftLeft@?$BigUnsigned@$0FE@@strings_internal@absl@@QAEXH@Z
-    ?ShouldInsertBackwards@container_internal@absl@@YA_NIPAC@Z
+    ?ShouldInsertBackwards@container_internal@absl@@YA_NIPBW4ctrl_t@12@@Z
     ?Signal@CondVar@absl@@QAEXXZ
     ?SignalAll@CondVar@absl@@QAEXXZ
     ?SimpleAtob@absl@@YA_NVstring_view@1@PA_N@Z
@@ -641,6 +680,7 @@ EXPORTS
     ?SizeofCordRepConcat@CordTestAccess@strings_internal@absl@@SAIXZ
     ?SizeofCordRepExternal@CordTestAccess@strings_internal@absl@@SAIXZ
     ?SizeofCordRepSubstring@CordTestAccess@strings_internal@absl@@SAIXZ
+    ?Skip@CordRepBtreeNavigator@cord_internal@absl@@QAE?AUPosition@123@I@Z
     ?SlowLock@SpinLock@base_internal@absl@@AAEXXZ
     ?SlowUnlock@SpinLock@base_internal@absl@@AAEXI@Z
     ?SnprintF@str_format_internal@absl@@YAHPADIVUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -661,6 +701,7 @@ EXPORTS
     ?StrReplaceAll@absl@@YAHV?$initializer_list@U?$pair@Vstring_view@absl@@V12@@__1@std@@@std@@PAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@3@@Z
     ?SubLength@CordRepRing@cord_internal@absl@@AAEXII@Z
     ?SubRing@CordRepRing@cord_internal@absl@@SAPAV123@PAV123@III@Z
+    ?SubTree@CordRepBtree@cord_internal@absl@@QAEPAUCordRep@23@II@Z
     ?Subcord@Cord@absl@@QBE?AV12@II@Z
     ?SubstituteAndAppendArray@substitute_internal@absl@@YAXPAV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@Vstring_view@2@PBV62@I@Z
     ?Summarize@str_format_internal@absl@@YA?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@VUntypedFormatSpecImpl@12@V?$Span@$$CBVFormatArgImpl@str_format_internal@absl@@@2@@Z
@@ -787,6 +828,8 @@ EXPORTS
     ?__vallocate@?$vector@VFormatArgImpl@str_format_internal@absl@@V?$allocator@VFormatArgImpl@str_format_internal@absl@@@__1@std@@@__1@std@@AAEXI@Z
     ?clear@?$__hash_table@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@V?$__unordered_map_hasher@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$__unordered_map_equal@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@23@U?$equal_to@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@U?$hash@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@@23@$00@23@V?$allocator@U?$__hash_value_type@V?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@PBVImpl@time_zone@cctz@time_internal@absl@@@__1@std@@@23@@__1@std@@QAEXXZ
     ?code@Status@absl@@QBE?AW4StatusCode@2@XZ
+    ?cord_btree_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
+    ?cord_btree_exhaustive_validation@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?cord_ring_buffer_enabled@cord_internal@absl@@3U?$atomic@_N@__1@std@@A
     ?day_difference@impl@detail@cctz@time_internal@absl@@YA_J_JCC0CC@Z
     ?description@time_zone@cctz@time_internal@absl@@QBE?AV?$basic_string@DU?$char_traits@D@__1@std@@V?$allocator@D@23@@__1@std@@XZ
author	Allan Sandfeld Jensen <allan.jensen@qt.io>	2021-10-26 13:57:00 +0200
committer	Allan Sandfeld Jensen <allan.jensen@qt.io>	2021-11-02 11:31:01 +0000
commit	1943b3c2a1dcee36c233724fc4ee7613d71b9cf6 (patch)
tree	8c1b5f12357025c197da5427ae02cfdc2f3570d6 /chromium/third_party/abseil-cpp
parent	21ba0c5d4bf8fba15dddd97cd693bad2358b77fd (diff)
download	qtwebengine-chromium-1943b3c2a1dcee36c233724fc4ee7613d71b9cf6.tar.gz