BASELINE: Update Chromium to 88.0.4324.208

Change-Id: I3ae87d23e4eff4b4a469685658740a213600c667
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

104 files changed, 2291 insertions, 1103 deletions

diff --git a/chromium/mojo/BUILD.gn b/chromium/mojo/BUILD.gn
index ea1cc00ddc4..c1fe06e9f60 100644
--- a/chromium/mojo/BUILD.gn
+++ b/chromium/mojo/BUILD.gn
@@ -59,7 +59,6 @@ test("mojo_perftests") {
       "//base",
       "//base/test:test_support",
       "//mojo/core:embedder_internal",
-      "//mojo/core:test_utils",
       "//mojo/core/embedder",
       "//testing/gtest",
     ]
diff --git a/chromium/mojo/DIR_METADATA b/chromium/mojo/DIR_METADATA
new file mode 100644
index 00000000000..06992d0dc06
--- /dev/null
+++ b/chromium/mojo/DIR_METADATA
@@ -0,0 +1,11 @@
+# Metadata information for this directory.
+#
+# For more information on DIR_METADATA files, see:
+#   https://source.chromium.org/chromium/infra/infra/+/master:go/src/infra/tools/dirmd/README.md
+#
+# For the schema of this file, see Metadata message:
+#   https://source.chromium.org/chromium/infra/infra/+/master:go/src/infra/tools/dirmd/proto/dir_metadata.proto
+
+monorail {
+  component: "Internals>Mojo"
+}
\ No newline at end of file
diff --git a/chromium/mojo/OWNERS b/chromium/mojo/OWNERS
index 5d06c5f1b75..15bd89fcb36 100644
--- a/chromium/mojo/OWNERS
+++ b/chromium/mojo/OWNERS
@@ -5,5 +5,3 @@ sky@chromium.org
 
 # For Fuchsia-specific changes:
 per-file *_fuchsia*=file://build/fuchsia/OWNERS
-
-# COMPONENT: Internals>Mojo
diff --git a/chromium/mojo/core/BUILD.gn b/chromium/mojo/core/BUILD.gn
index db6af19ea9f..89add521c60 100644
--- a/chromium/mojo/core/BUILD.gn
+++ b/chromium/mojo/core/BUILD.gn
@@ -12,13 +12,6 @@ if (is_mac) {
   import("//third_party/protobuf/proto_library.gni")
 }
 
-# This file depends on the legacy global sources assignment filter. It should
-# be converted to check target platform before assigning source files to the
-# sources variable. Remove this import and set_sources_assignment_filter call
-# when the file has been converted. See https://crbug.com/1018739 for details.
-import("//build/config/deprecated_default_sources_assignment_filter.gni")
-set_sources_assignment_filter(deprecated_default_sources_assignment_filter)
-
 component("embedder_internal") {
   output_name = "mojo_core_embedder_internal"
   public_deps = [ ":impl_for_embedder" ]
@@ -81,9 +74,7 @@ template("core_impl_source_set") {
     sources = [
       "atomic_flag.h",
       "broker.h",
-      "broker_win.cc",
       "channel.cc",
-      "channel_win.cc",
       "configuration.cc",
       "connection_params.cc",
       "core.cc",
@@ -163,6 +154,10 @@ template("core_impl_source_set") {
     }
 
     if (is_win) {
+      sources += [
+        "broker_win.cc",
+        "channel_win.cc",
+      ]
       cflags = [ "/wd4324" ]  # Structure was padded due to __declspec(align()),
                               # which is uninteresting.
     }
@@ -269,27 +264,6 @@ if (is_chromeos || is_linux || is_android || is_win) {
   }
 }
 
-source_set("test_utils") {
-  testonly = true
-
-  sources = [
-    "test_utils.cc",
-    "test_utils.h",
-  ]
-
-  public_deps = [
-    "//mojo/public/c/system",
-    "//mojo/public/cpp/system",
-  ]
-
-  deps = [
-    "//base",
-    "//base/test:test_support",
-    "//mojo/core/test:test_support",
-    "//testing/gtest:gtest",
-  ]
-}
-
 source_set("test_sources") {
   testonly = true
   sources = [
@@ -316,12 +290,12 @@ source_set("test_sources") {
       "data_pipe_unittest.cc",
       "invitation_unittest.cc",
       "multiprocess_message_pipe_unittest.cc",
+      "node_controller_unittest.cc",
       "platform_wrapper_unittest.cc",
     ]
   }
 
   deps = [
-    ":test_utils",
     "//base",
     "//base/test:test_support",
     "//mojo/core:embedder_internal",
diff --git a/chromium/mojo/core/channel.h b/chromium/mojo/core/channel.h
index 8d705c570bf..1a8ca65f613 100644
--- a/chromium/mojo/core/channel.h
+++ b/chromium/mojo/core/channel.h
@@ -278,6 +278,11 @@ class MOJO_SYSTEM_IMPL_EXPORT Channel
       HandlePolicy handle_policy,
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner);
 
+#if defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_MAC)
+  // At this point only ChannelPosix needs InitFeatures.
+  static void set_posix_use_writev(bool use_writev);
+#endif
+
   // Allows the caller to change the Channel's HandlePolicy after construction.
   void set_handle_policy(HandlePolicy policy) { handle_policy_ = policy; }
 
diff --git a/chromium/mojo/core/channel_fuzzer.cc b/chromium/mojo/core/channel_fuzzer.cc
index cb41000d645..2fb651700c8 100644
--- a/chromium/mojo/core/channel_fuzzer.cc
+++ b/chromium/mojo/core/channel_fuzzer.cc
@@ -4,7 +4,7 @@
 
 #include <stdint.h>
 
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/message_loop/message_pump_type.h"
 #include "base/no_destructor.h"
 #include "base/run_loop.h"
diff --git a/chromium/mojo/core/channel_posix.cc b/chromium/mojo/core/channel_posix.cc
index d7d9d6cfee1..141316d1c13 100644
--- a/chromium/mojo/core/channel_posix.cc
+++ b/chromium/mojo/core/channel_posix.cc
@@ -8,6 +8,7 @@
 #include <sys/socket.h>
 
 #include <algorithm>
+#include <atomic>
 #include <limits>
 #include <memory>
 
@@ -28,6 +29,7 @@
 #include "mojo/public/cpp/platform/socket_utils_posix.h"
 
 #if !defined(OS_NACL)
+#include <limits.h>
 #include <sys/uio.h>
 #endif
 
@@ -36,6 +38,10 @@ namespace core {
 
 namespace {
 
+#if !defined(OS_NACL)
+std::atomic<bool> g_use_writev{false};
+#endif
+
 const size_t kMaxBatchReadCapacity = 256 * 1024;
 
 // A view over a Channel::Message object. The write queue uses these since
@@ -89,6 +95,10 @@ class MessageView {
     num_handles_sent_ = num_handles_sent;
   }
 
+  size_t num_handles_remaining() const {
+    return handles_.size() - num_handles_sent_;
+  }
+
  private:
   Channel::MessagePtr message_;
   size_t offset_;
@@ -447,6 +457,11 @@ class ChannelPosix : public Channel,
   }
 
   bool FlushOutgoingMessagesNoLock() {
+#if !defined(OS_NACL)
+    if (g_use_writev)
+      return FlushOutgoingMessagesWritevNoLock();
+#endif
+
     base::circular_deque<MessageView> messages;
     std::swap(outgoing_messages_, messages);
 
@@ -478,6 +493,112 @@ class ChannelPosix : public Channel,
     return true;
   }
 
+#if !defined(OS_NACL)
+  bool WriteOutgoingMessagesWithWritev() {
+    if (outgoing_messages_.empty())
+      return true;
+
+    // If all goes well we can submit a writev(2) with a iovec of size
+    // outgoing_messages_.size() but never more than the kernel allows.
+    size_t num_messages_to_send =
+        std::min<size_t>(IOV_MAX, outgoing_messages_.size());
+    iovec iov[num_messages_to_send];
+    memset(&iov[0], 0, sizeof(iov));
+
+    // Populate the iov.
+    size_t num_iovs_set = 0;
+    for (auto it = outgoing_messages_.begin();
+         num_iovs_set < num_messages_to_send; ++it) {
+      if (it->num_handles_remaining() > 0) {
+        // We can't send handles with writev(2) so stop at this message.
+        break;
+      }
+
+      iov[num_iovs_set].iov_base = const_cast<void*>(it->data());
+      iov[num_iovs_set].iov_len = it->data_num_bytes();
+      num_iovs_set++;
+    }
+
+    UMA_HISTOGRAM_COUNTS_1000("Mojo.Channel.WritevBatchedMessages",
+                              num_iovs_set);
+
+    size_t iov_offset = 0;
+    while (iov_offset < num_iovs_set) {
+      ssize_t bytes_written = SocketWritev(socket_.get(), &iov[iov_offset],
+                                           num_iovs_set - iov_offset);
+      if (bytes_written < 0) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK) {
+          WaitForWriteOnIOThreadNoLock();
+          return true;
+        }
+        return false;
+      }
+
+      // Let's walk our outgoing_messages_ popping off outgoing_messages_
+      // that were fully written.
+      size_t bytes_remaining = bytes_written;
+      while (bytes_remaining > 0) {
+        if (bytes_remaining >= outgoing_messages_.front().data_num_bytes()) {
+          // This message was fully written.
+          bytes_remaining -= outgoing_messages_.front().data_num_bytes();
+          outgoing_messages_.pop_front();
+          iov_offset++;
+        } else {
+          // This message was partially written, account for what was
+          // already written.
+          outgoing_messages_.front().advance_data_offset(bytes_remaining);
+          bytes_remaining = 0;
+
+          // Update the iov too as we will call writev again.
+          iov[iov_offset].iov_base =
+              const_cast<void*>(outgoing_messages_.front().data());
+          iov[iov_offset].iov_len = outgoing_messages_.front().data_num_bytes();
+        }
+      }
+    }
+
+    return true;
+  }
+
+  // FlushOutgoingMessagesWritevNoLock is equivalent to
+  // FlushOutgoingMessagesNoLock except it looks for opportunities to make only
+  // a single write syscall by using writev(2) instead of write(2). In most
+  // situations this is very straight forward; however, when a handle needs to
+  // be transferred we cannot use writev(2) and instead will fall back to the
+  // standard write.
+  bool FlushOutgoingMessagesWritevNoLock() {
+    do {
+      // If the first message contains a handle we will flush it first using a
+      // standard write, we will also use the standard write if we only have a
+      // single message.
+      while (!outgoing_messages_.empty() &&
+             (outgoing_messages_.front().num_handles_remaining() > 0 ||
+              outgoing_messages_.size() == 1)) {
+        MessageView message = std::move(outgoing_messages_.front());
+
+        outgoing_messages_.pop_front();
+        size_t messages_before_write = outgoing_messages_.size();
+        if (!WriteNoLock(std::move(message)))
+          return false;
+
+        if (outgoing_messages_.size() > messages_before_write) {
+          // It was re-queued by WriteNoLock.
+          return true;
+        }
+      }
+
+      if (!WriteOutgoingMessagesWithWritev())
+        return false;
+
+      // At this point if we have more messages then it's either because we
+      // exceeded IOV_MAX OR it's because we ran into a FileHandle. Either way
+      // we just start the process all over again and it will flush any
+      // FileHandles before attempting writev(2) again.
+    } while (!outgoing_messages_.empty());
+    return true;
+  }
+#endif  // !defined(OS_NACL)
+
 #if defined(OS_IOS)
   bool OnControlMessage(Message::MessageType message_type,
                         const void* payload,
@@ -601,6 +722,13 @@ class ChannelPosix : public Channel,
 }  // namespace
 
 // static
+#if !defined(OS_NACL)
+void Channel::set_posix_use_writev(bool use_writev) {
+  g_use_writev = use_writev;
+}
+#endif
+
+// static
 scoped_refptr<Channel> Channel::Create(
     Delegate* delegate,
     ConnectionParams connection_params,
diff --git a/chromium/mojo/core/channel_unittest.cc b/chromium/mojo/core/channel_unittest.cc
index 4fcb57b9651..58d6ee44ad6 100644
--- a/chromium/mojo/core/channel_unittest.cc
+++ b/chromium/mojo/core/channel_unittest.cc
@@ -14,7 +14,7 @@
 #include "base/process/process_metrics.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/task_environment.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
diff --git a/chromium/mojo/core/core.cc b/chromium/mojo/core/core.cc
index 9f344cfab31..61444a3dec1 100644
--- a/chromium/mojo/core/core.cc
+++ b/chromium/mojo/core/core.cc
@@ -137,7 +137,7 @@ void Core::SetIOTaskRunner(
 NodeController* Core::GetNodeController() {
   base::AutoLock lock(node_controller_lock_);
   if (!node_controller_)
-    node_controller_.reset(new NodeController(this));
+    node_controller_ = std::make_unique<NodeController>();
   return node_controller_.get();
 }
 
diff --git a/chromium/mojo/core/core_test_base.h b/chromium/mojo/core/core_test_base.h
index 5d37d252c2e..ebc5fe154e3 100644
--- a/chromium/mojo/core/core_test_base.h
+++ b/chromium/mojo/core/core_test_base.h
@@ -9,7 +9,6 @@
 
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/types.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
diff --git a/chromium/mojo/core/core_unittest.cc b/chromium/mojo/core/core_unittest.cc
index 8846051ad03..0d2024ccd9a 100644
--- a/chromium/mojo/core/core_unittest.cc
+++ b/chromium/mojo/core/core_unittest.cc
@@ -11,7 +11,6 @@
 #include "base/bind.h"
 #include "build/build_config.h"
 #include "mojo/core/core_test_base.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/cpp/system/wait.h"
 
 #if defined(OS_WIN)
@@ -35,7 +34,7 @@ TEST_F(CoreTest, GetTimeTicksNow) {
   const MojoTimeTicks start = core()->GetTimeTicksNow();
   ASSERT_NE(static_cast<MojoTimeTicks>(0), start)
       << "GetTimeTicksNow should return nonzero value";
-  test::Sleep(test::DeadlineFromMilliseconds(15));
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(15));
   const MojoTimeTicks finish = core()->GetTimeTicksNow();
   // Allow for some fuzz in sleep.
   ASSERT_GE((finish - start), static_cast<MojoTimeTicks>(8000))
diff --git a/chromium/mojo/core/data_pipe_unittest.cc b/chromium/mojo/core/data_pipe_unittest.cc
index 9ff3e1668bf..395e8d8fdac 100644
--- a/chromium/mojo/core/data_pipe_unittest.cc
+++ b/chromium/mojo/core/data_pipe_unittest.cc
@@ -16,7 +16,6 @@
 #include "build/build_config.h"
 #include "mojo/core/embedder/embedder.h"
 #include "mojo/core/test/mojo_test_base.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/data_pipe.h"
 #include "mojo/public/c/system/functions.h"
 #include "mojo/public/c/system/message_pipe.h"
@@ -45,6 +44,28 @@ const int kMultiprocessMaxIter = 5;
 // Capacity that will cause data pipe creation to fail.
 constexpr size_t kOversizedCapacity = std::numeric_limits<uint32_t>::max();
 
+// A timeout smaller than |TestTimeouts::tiny_timeout()|, as a |MojoDeadline|.
+// Warning: This may lead to flakiness, but this is unavoidable if, e.g., you're
+// trying to ensure that functions with timeouts are reasonably accurate. We
+// want this to be as small as possible without causing too much flakiness.
+base::TimeDelta EpsilonDeadline() {
+  const int64_t tiny_timeout = TestTimeouts::tiny_timeout().InMicroseconds();
+// Originally, our epsilon timeout was 10 ms, which was mostly fine but flaky on
+// some Windows bots. I don't recall ever seeing flakes on other bots. At 30 ms
+// tests seem reliable on Windows bots, but not at 25 ms. We'd like this timeout
+// to be as small as possible (see the description in the .h file).
+//
+// Currently, |tiny_timeout()| is usually 100 ms (possibly scaled under ASAN,
+// etc.). Based on this, set it to (usually be) 30 ms on Windows and 20 ms
+// elsewhere.
+#if defined(OS_WIN) || defined(OS_ANDROID)
+  const int64_t deadline = (tiny_timeout * 3) / 10;
+#else
+  const int64_t deadline = (tiny_timeout * 2) / 10;
+#endif
+  return base::TimeDelta::FromMicroseconds(deadline);
+}
+
 // TODO(rockot): There are many uses of ASSERT where EXPECT would be more
 // appropriate. Fix this.
 
@@ -948,7 +969,7 @@ TEST_F(DataPipeTest, AllOrNone) {
     if (num_bytes >= 10u * sizeof(int32_t))
       break;
 
-    test::Sleep(test::EpsilonDeadline());
+    base::PlatformThread::Sleep(EpsilonDeadline());
   }
   ASSERT_EQ(10u * sizeof(int32_t), num_bytes);
 
@@ -1154,7 +1175,7 @@ TEST_F(DataPipeTest, WriteCloseProducerRead) {
     if (num_bytes >= 2u * kTestDataSize)
       break;
 
-    test::Sleep(test::EpsilonDeadline());
+    base::PlatformThread::Sleep(EpsilonDeadline());
   }
   ASSERT_EQ(2u * kTestDataSize, num_bytes);
 
@@ -1423,7 +1444,7 @@ TEST_F(DataPipeTest, TwoPhaseMoreInvalidArguments) {
 
   // Wait a bit, to make sure that if a signal were (incorrectly) sent, it'd
   // have time to propagate.
-  test::Sleep(test::EpsilonDeadline());
+  base::PlatformThread::Sleep(EpsilonDeadline());
 
   // Still no data.
   num_bytes = 1000u;
@@ -1441,7 +1462,7 @@ TEST_F(DataPipeTest, TwoPhaseMoreInvalidArguments) {
   ASSERT_EQ(MOJO_RESULT_FAILED_PRECONDITION, EndWriteData(0u));
 
   // Wait a bit (as above).
-  test::Sleep(test::EpsilonDeadline());
+  base::PlatformThread::Sleep(EpsilonDeadline());
 
   // Still no data.
   num_bytes = 1000u;
@@ -1460,7 +1481,7 @@ TEST_F(DataPipeTest, TwoPhaseMoreInvalidArguments) {
   ASSERT_EQ(MOJO_RESULT_FAILED_PRECONDITION, EndWriteData(0u));
 
   // Wait a bit (as above).
-  test::Sleep(test::EpsilonDeadline());
+  base::PlatformThread::Sleep(EpsilonDeadline());
 
   // Still no data.
   num_bytes = 1000u;
@@ -1705,7 +1726,7 @@ bool ReadAllData(MojoHandle consumer,
       if (num_bytes == 0) {
         if (expect_empty) {
           // Expect no more data.
-          test::Sleep(test::TinyDeadline());
+          base::PlatformThread::Sleep(TestTimeouts::tiny_timeout());
           MojoReadDataOptions options;
           options.struct_size = sizeof(options);
           options.flags = MOJO_READ_DATA_FLAG_QUERY;
diff --git a/chromium/mojo/core/embedder/embedder.cc b/chromium/mojo/core/embedder/embedder.cc
index 3a4e3172938..29b6d058e91 100644
--- a/chromium/mojo/core/embedder/embedder.cc
+++ b/chromium/mojo/core/embedder/embedder.cc
@@ -5,10 +5,14 @@
 #include "mojo/core/embedder/embedder.h"
 
 #include <stdint.h>
+#include <atomic>
 #include <utility>
 
+#include "base/feature_list.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_runner.h"
+#include "build/build_config.h"
+#include "mojo/core/channel.h"
 #include "mojo/core/configuration.h"
 #include "mojo/core/core.h"
 #include "mojo/core/entrypoints.h"
@@ -18,6 +22,21 @@
 namespace mojo {
 namespace core {
 
+namespace {
+#if defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_MAC)
+const base::Feature kMojoPosixUseWritev{"MojoPosixUseWritev",
+                                        base::FEATURE_DISABLED_BY_DEFAULT};
+#endif
+}  // namespace
+
+// InitFeatures will be called as soon as the base::FeatureList is initialized.
+void InitFeatures() {
+#if defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_MAC)
+  Channel::set_posix_use_writev(
+      base::FeatureList::IsEnabled(kMojoPosixUseWritev));
+#endif
+}
+
 void Init(const Configuration& configuration) {
   internal::g_configuration = configuration;
   InitializeCore();
diff --git a/chromium/mojo/core/embedder/embedder.h b/chromium/mojo/core/embedder/embedder.h
index 575b301468d..56b8bb6c9d5 100644
--- a/chromium/mojo/core/embedder/embedder.h
+++ b/chromium/mojo/core/embedder/embedder.h
@@ -38,6 +38,14 @@ COMPONENT_EXPORT(MOJO_CORE_EMBEDDER) void Init();
 COMPONENT_EXPORT(MOJO_CORE_EMBEDDER)
 scoped_refptr<base::SingleThreadTaskRunner> GetIOTaskRunner();
 
+// InitFeatures will be called as soon as the base::FeatureList is initialized.
+// NOTE: This is temporarily necessary because of how Mojo is started with
+// respect to base::FeatureList.
+//
+// TODO(rockot): Remove once a long term solution is in place for using
+// base::Features inside of Mojo.
+COMPONENT_EXPORT(MOJO_CORE_EMBEDDER) void InitFeatures();
+
 }  // namespace core
 }  // namespace mojo
 
diff --git a/chromium/mojo/core/embedder/scoped_ipc_support.cc b/chromium/mojo/core/embedder/scoped_ipc_support.cc
index 4bfbc9e0775..0fbf446eca9 100644
--- a/chromium/mojo/core/embedder/scoped_ipc_support.cc
+++ b/chromium/mojo/core/embedder/scoped_ipc_support.cc
@@ -5,7 +5,7 @@
 #include "mojo/core/embedder/scoped_ipc_support.h"
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_restrictions.h"
 #include "mojo/core/core.h"
diff --git a/chromium/mojo/core/embedder_unittest.cc b/chromium/mojo/core/embedder_unittest.cc
index 5d85b367e2c..7f24ea6b159 100644
--- a/chromium/mojo/core/embedder_unittest.cc
+++ b/chromium/mojo/core/embedder_unittest.cc
@@ -30,7 +30,6 @@
 #include "mojo/core/core.h"
 #include "mojo/core/shared_buffer_dispatcher.h"
 #include "mojo/core/test/mojo_test_base.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/core.h"
 #include "mojo/public/cpp/system/handle.h"
 #include "mojo/public/cpp/system/message_pipe.h"
@@ -47,7 +46,7 @@ MojoResult CreateSharedBufferFromRegion(T&& region, MojoHandle* handle) {
   scoped_refptr<SharedBufferDispatcher> buffer;
   MojoResult result =
       SharedBufferDispatcher::CreateFromPlatformSharedMemoryRegion(
-          T::TakeHandleForSerialization(std::move(region)), &buffer);
+          T::TakeHandleForSerialization(std::forward<T>(region)), &buffer);
   if (result != MOJO_RESULT_OK)
     return result;
 
diff --git a/chromium/mojo/core/invitation_unittest.cc b/chromium/mojo/core/invitation_unittest.cc
index 684bbfe2a41..c88c20bf83a 100644
--- a/chromium/mojo/core/invitation_unittest.cc
+++ b/chromium/mojo/core/invitation_unittest.cc
@@ -18,7 +18,7 @@
 #include "base/process/process.h"
 #include "base/run_loop.h"
 #include "base/synchronization/lock.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/multiprocess_test.h"
 #include "base/test/task_environment.h"
 #include "base/threading/sequenced_task_runner_handle.h"
diff --git a/chromium/mojo/core/message_pipe_dispatcher.cc b/chromium/mojo/core/message_pipe_dispatcher.cc
index e17fdabc2d3..980d01ceccc 100644
--- a/chromium/mojo/core/message_pipe_dispatcher.cc
+++ b/chromium/mojo/core/message_pipe_dispatcher.cc
@@ -199,42 +199,51 @@ MojoResult MessagePipeDispatcher::ReadMessage(
 }
 
 MojoResult MessagePipeDispatcher::SetQuota(MojoQuotaType type, uint64_t limit) {
-  base::AutoLock lock(signal_lock_);
-
-  switch (type) {
-    case MOJO_QUOTA_TYPE_RECEIVE_QUEUE_LENGTH:
-      if (limit == MOJO_QUOTA_LIMIT_NONE)
-        receive_queue_length_limit_.reset();
-      else
-        receive_queue_length_limit_ = limit;
-      break;
-
-    case MOJO_QUOTA_TYPE_RECEIVE_QUEUE_MEMORY_SIZE:
-      if (limit == MOJO_QUOTA_LIMIT_NONE)
-        receive_queue_memory_size_limit_.reset();
-      else
-        receive_queue_memory_size_limit_ = limit;
-      break;
-
-    case MOJO_QUOTA_TYPE_UNREAD_MESSAGE_COUNT:
-      if (limit == MOJO_QUOTA_LIMIT_NONE) {
-        unread_message_count_limit_.reset();
-        node_controller_->node()->SetAcknowledgeRequestInterval(port_, 0);
-      } else {
-        unread_message_count_limit_ = limit;
-        // Setting the acknowledge request interval for the port to half the
-        // unread quota limit, means the ack roundtrip has half the window to
-        // catch up with sent messages. In other words, if the producer is
-        // producing messages at a steady rate of limit/2 packets per message
-        // round trip or lower, the quota limit won't be exceeded. This is
-        // assuming the consumer is consuming messages at the same rate.
-        node_controller_->node()->SetAcknowledgeRequestInterval(
-            port_, (limit + 1) / 2);
-      }
-      break;
+  base::Optional<uint64_t> new_ack_request_interval;
+  {
+    base::AutoLock lock(signal_lock_);
+    switch (type) {
+      case MOJO_QUOTA_TYPE_RECEIVE_QUEUE_LENGTH:
+        if (limit == MOJO_QUOTA_LIMIT_NONE)
+          receive_queue_length_limit_.reset();
+        else
+          receive_queue_length_limit_ = limit;
+        break;
+
+      case MOJO_QUOTA_TYPE_RECEIVE_QUEUE_MEMORY_SIZE:
+        if (limit == MOJO_QUOTA_LIMIT_NONE)
+          receive_queue_memory_size_limit_.reset();
+        else
+          receive_queue_memory_size_limit_ = limit;
+        break;
+
+      case MOJO_QUOTA_TYPE_UNREAD_MESSAGE_COUNT:
+        if (limit == MOJO_QUOTA_LIMIT_NONE) {
+          unread_message_count_limit_.reset();
+          new_ack_request_interval = 0;
+        } else {
+          unread_message_count_limit_ = limit;
+          // Setting the acknowledge request interval for the port to half the
+          // unread quota limit, means the ack roundtrip has half the window to
+          // catch up with sent messages. In other words, if the producer is
+          // producing messages at a steady rate of limit/2 packets per message
+          // round trip or lower, the quota limit won't be exceeded. This is
+          // assuming the consumer is consuming messages at the same rate.
+          new_ack_request_interval = (limit + 1) / 2;
+        }
+        break;
+
+      default:
+        return MOJO_RESULT_INVALID_ARGUMENT;
+    }
+  }
 
-    default:
-      return MOJO_RESULT_INVALID_ARGUMENT;
+  if (new_ack_request_interval.has_value()) {
+    // NOTE: It is not safe to call into SetAcknowledgeRequestInterval while
+    // holding a `signal_lock_`, as it may re-enter this object when the peer is
+    // in the same process.
+    node_controller_->node()->SetAcknowledgeRequestInterval(
+        port_, *new_ack_request_interval);
   }
 
   return MOJO_RESULT_OK;
diff --git a/chromium/mojo/core/message_pipe_perftest.cc b/chromium/mojo/core/message_pipe_perftest.cc
index af832586393..f7ae32e345c 100644
--- a/chromium/mojo/core/message_pipe_perftest.cc
+++ b/chromium/mojo/core/message_pipe_perftest.cc
@@ -9,7 +9,7 @@
 #include <utility>
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/check_op.h"
 #include "base/macros.h"
 #include "base/strings/stringprintf.h"
@@ -19,7 +19,6 @@
 #include "mojo/core/handle_signals_state.h"
 #include "mojo/core/test/mojo_test_base.h"
 #include "mojo/core/test/test_utils.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/functions.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 #include "testing/gtest/include/gtest/gtest.h"
diff --git a/chromium/mojo/core/message_pipe_unittest.cc b/chromium/mojo/core/message_pipe_unittest.cc
index 20c71ff4549..9aa13f69f2f 100644
--- a/chromium/mojo/core/message_pipe_unittest.cc
+++ b/chromium/mojo/core/message_pipe_unittest.cc
@@ -14,7 +14,6 @@
 #include "base/memory/ref_counted.h"
 #include "build/build_config.h"
 #include "mojo/core/test/mojo_test_base.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/core.h"
 #include "mojo/public/c/system/types.h"
 #include "mojo/public/cpp/system/message_pipe.h"
diff --git a/chromium/mojo/core/multiprocess_message_pipe_unittest.cc b/chromium/mojo/core/multiprocess_message_pipe_unittest.cc
index bdce6c7fd8a..26e2c80b0d2 100644
--- a/chromium/mojo/core/multiprocess_message_pipe_unittest.cc
+++ b/chromium/mojo/core/multiprocess_message_pipe_unittest.cc
@@ -26,7 +26,6 @@
 #include "mojo/core/handle_signals_state.h"
 #include "mojo/core/test/mojo_test_base.h"
 #include "mojo/core/test/test_utils.h"
-#include "mojo/core/test_utils.h"
 #include "mojo/public/c/system/buffer.h"
 #include "mojo/public/c/system/functions.h"
 #include "mojo/public/c/system/types.h"
diff --git a/chromium/mojo/core/node_channel.cc b/chromium/mojo/core/node_channel.cc
index 5db339ec802..e9cc9f23c2f 100644
--- a/chromium/mojo/core/node_channel.cc
+++ b/chromium/mojo/core/node_channel.cc
@@ -45,6 +45,8 @@ enum class MessageType : uint32_t {
   BIND_BROKER_HOST,
 };
 
+#pragma pack(push, 1)
+
 struct Header {
   MessageType type;
   uint32_t padding;
@@ -130,6 +132,8 @@ struct EventMessageFromRelayData {
 };
 #endif
 
+#pragma pack(pop)
+
 template <typename DataType>
 Channel::MessagePtr CreateMessage(MessageType type,
                                   size_t payload_size,
diff --git a/chromium/mojo/core/node_channel_fuzzer.cc b/chromium/mojo/core/node_channel_fuzzer.cc
index 54fe757e0de..33188323f05 100644
--- a/chromium/mojo/core/node_channel_fuzzer.cc
+++ b/chromium/mojo/core/node_channel_fuzzer.cc
@@ -4,7 +4,7 @@
 
 #include <stdint.h>
 
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/message_loop/message_pump_type.h"
 #include "base/no_destructor.h"
 #include "base/run_loop.h"
diff --git a/chromium/mojo/core/node_channel_unittest.cc b/chromium/mojo/core/node_channel_unittest.cc
index 13c46f13fea..e89f5a13bb0 100644
--- a/chromium/mojo/core/node_channel_unittest.cc
+++ b/chromium/mojo/core/node_channel_unittest.cc
@@ -4,7 +4,7 @@
 
 #include "mojo/core/node_channel.h"
 
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/message_loop/message_pump_type.h"
 #include "base/test/task_environment.h"
diff --git a/chromium/mojo/core/node_controller.cc b/chromium/mojo/core/node_controller.cc
index 029bd350b08..823a4619efa 100644
--- a/chromium/mojo/core/node_controller.cc
+++ b/chromium/mojo/core/node_controller.cc
@@ -21,7 +21,6 @@
 #include "mojo/core/broker.h"
 #include "mojo/core/broker_host.h"
 #include "mojo/core/configuration.h"
-#include "mojo/core/core.h"
 #include "mojo/core/request_context.h"
 #include "mojo/core/user_message_impl.h"
 #include "mojo/public/cpp/platform/named_platform_channel.h"
@@ -146,10 +145,8 @@ class ThreadDestructionObserver
 
 NodeController::~NodeController() = default;
 
-NodeController::NodeController(Core* core)
-    : core_(core),
-      name_(GetRandomNodeName()),
-      node_(new ports::Node(name_, this)) {
+NodeController::NodeController()
+    : name_(GetRandomNodeName()), node_(new ports::Node(name_, this)) {
   DVLOG(1) << "Initializing node " << name_;
 }
 
@@ -588,10 +585,17 @@ void NodeController::AddPeer(const ports::NodeName& name,
   }
 }
 
-void NodeController::DropPeer(const ports::NodeName& name,
+void NodeController::DropPeer(const ports::NodeName& node_name,
                               NodeChannel* channel) {
   DCHECK(io_task_runner_->RunsTasksInCurrentSequence());
 
+  // NOTE: Either the `peers_` erasure or the `pending_invitations_` erasure
+  // below, if executed, may drop the last reference to the named NodeChannel
+  // and thus result in its deletion. The passed `node_name` argument may be
+  // owned by that same NodeChannel, so we make a copy of it here to avoid
+  // potentially unsafe references further below.
+  ports::NodeName name = node_name;
+
   {
     base::AutoLock lock(peers_lock_);
     auto it = peers_.find(name);
diff --git a/chromium/mojo/core/node_controller.h b/chromium/mojo/core/node_controller.h
index f35237f4eb5..b0ddd290973 100644
--- a/chromium/mojo/core/node_controller.h
+++ b/chromium/mojo/core/node_controller.h
@@ -52,11 +52,10 @@ class MOJO_SYSTEM_IMPL_EXPORT NodeController : public ports::NodeDelegate,
   };
 
   // |core| owns and out-lives us.
-  explicit NodeController(Core* core);
+  NodeController();
   ~NodeController() override;
 
   const ports::NodeName& name() const { return name_; }
-  Core* core() const { return core_; }
   ports::Node* node() const { return node_.get(); }
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner() const {
     return io_task_runner_;
@@ -135,6 +134,8 @@ class MOJO_SYSTEM_IMPL_EXPORT NodeController : public ports::NodeDelegate,
       base::span<const unsigned char> data);
   static void DeserializeMessageAsEventForFuzzer(Channel::MessagePtr message);
 
+  scoped_refptr<NodeChannel> GetBrokerChannel();
+
  private:
   friend Core;
 
@@ -176,7 +177,6 @@ class MOJO_SYSTEM_IMPL_EXPORT NodeController : public ports::NodeDelegate,
 
   scoped_refptr<NodeChannel> GetPeerChannel(const ports::NodeName& name);
   scoped_refptr<NodeChannel> GetInviterChannel();
-  scoped_refptr<NodeChannel> GetBrokerChannel();
 
   void AddPeer(const ports::NodeName& name,
                scoped_refptr<NodeChannel> channel,
@@ -254,7 +254,6 @@ class MOJO_SYSTEM_IMPL_EXPORT NodeController : public ports::NodeDelegate,
   void ForceDisconnectProcessForTestingOnIOThread(base::ProcessId process_id);
 
   // These are safe to access from any thread as long as the Node is alive.
-  Core* const core_;
   const ports::NodeName name_;
   const std::unique_ptr<ports::Node> node_;
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
@@ -319,7 +318,7 @@ class MOJO_SYSTEM_IMPL_EXPORT NodeController : public ports::NodeDelegate,
   AtomicFlag shutdown_callback_flag_;
 
   // All other fields below must only be accessed on the I/O thread, i.e., the
-  // thread on which core_->io_task_runner() runs tasks.
+  // thread on which `io_task_runner_` runs tasks.
 
   // Channels to invitees during handshake.
   NodeMap pending_invitations_;
diff --git a/chromium/mojo/core/node_controller_unittest.cc b/chromium/mojo/core/node_controller_unittest.cc
new file mode 100644
index 00000000000..316e1623763
--- /dev/null
+++ b/chromium/mojo/core/node_controller_unittest.cc
@@ -0,0 +1,42 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/logging.h"
+#include "mojo/core/core.h"
+#include "mojo/core/test/mojo_test_base.h"
+#include "mojo/public/c/system/types.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace core {
+namespace {
+
+using NodeControllerTest = test::MojoTestBase;
+
+TEST_F(NodeControllerTest, AcceptInvitationFailure) {
+  // Spawn a child process that will send an invalid AcceptInvitation
+  // NodeChannel message. This is a regression test for
+  // https://crbug.com/1162198.
+  RunTestClient("SendInvalidAcceptInvitation",
+                [&](MojoHandle h) { WriteMessage(h, "hi"); });
+}
+
+DEFINE_TEST_CLIENT_TEST_WITH_PIPE(SendInvalidAcceptInvitation,
+                                  NodeControllerTest,
+                                  h) {
+  // A little communication to synchronize against Mojo bringup. By the time
+  // this read completes, we must have an internal NodeController with the
+  // parent test process connected as its broker.
+  EXPECT_EQ("hi", ReadMessage(h));
+
+  // Send an unexpected AcceptInvitation message to the parent process. This
+  // exercises the regression code path in the parent process.
+  NodeController* controller = Core::Get()->GetNodeController();
+  scoped_refptr<NodeChannel> channel = controller->GetBrokerChannel();
+  channel->AcceptInvitation(ports::NodeName{0, 0}, ports::NodeName{0, 0});
+}
+
+}  // namespace
+}  // namespace core
+}  // namespace mojo
diff --git a/chromium/mojo/core/ports/node.cc b/chromium/mojo/core/ports/node.cc
index 5b2558a0465..7907b38d4e6 100644
--- a/chromium/mojo/core/ports/node.cc
+++ b/chromium/mojo/core/ports/node.cc
@@ -920,7 +920,8 @@ int Node::OnUserMessageReadAckRequest(
     }
   }
 
-  delegate_->ForwardEvent(peer_node_name, std::move(event_to_send));
+  if (event_to_send)
+    delegate_->ForwardEvent(peer_node_name, std::move(event_to_send));
 
   return OK;
 }
diff --git a/chromium/mojo/core/test/BUILD.gn b/chromium/mojo/core/test/BUILD.gn
index 9d0d150771d..d3025e4c1c2 100644
--- a/chromium/mojo/core/test/BUILD.gn
+++ b/chromium/mojo/core/test/BUILD.gn
@@ -4,13 +4,6 @@
 
 import("//third_party/protobuf/proto_library.gni")
 
-# This file depends on the legacy global sources assignment filter. It should
-# be converted to check target platform before assigning source files to the
-# sources variable. Remove this import and set_sources_assignment_filter call
-# when the file has been converted. See https://crbug.com/1018739 for details.
-import("//build/config/deprecated_default_sources_assignment_filter.gni")
-set_sources_assignment_filter(deprecated_default_sources_assignment_filter)
-
 static_library("test_support") {
   testonly = true
   sources = [
@@ -19,7 +12,6 @@ static_library("test_support") {
     "mojo_test_base.cc",
     "mojo_test_base.h",
     "test_utils.h",
-    "test_utils_win.cc",
   ]
 
   if (!is_ios) {
@@ -29,6 +21,10 @@ static_library("test_support") {
     ]
   }
 
+  if (is_win) {
+    sources += [ "test_utils_win.cc" ]
+  }
+
   if (is_fuchsia || is_posix) {
     sources += [ "test_utils.cc" ]
   }
diff --git a/chromium/mojo/core/test_utils.cc b/chromium/mojo/core/test_utils.cc
deleted file mode 100644
index acbfca018af..00000000000
--- a/chromium/mojo/core/test_utils.cc
+++ /dev/null
@@ -1,74 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "mojo/core/test_utils.h"
-
-#include <stdint.h>
-
-#include <limits>
-
-#include "base/check_op.h"
-#include "base/test/test_timeouts.h"
-#include "base/threading/platform_thread.h"  // For |Sleep()|.
-#include "build/build_config.h"
-
-namespace mojo {
-namespace core {
-namespace test {
-
-MojoDeadline DeadlineFromMilliseconds(unsigned milliseconds) {
-  return static_cast<MojoDeadline>(milliseconds) * 1000;
-}
-
-MojoDeadline EpsilonDeadline() {
-// Originally, our epsilon timeout was 10 ms, which was mostly fine but flaky on
-// some Windows bots. I don't recall ever seeing flakes on other bots. At 30 ms
-// tests seem reliable on Windows bots, but not at 25 ms. We'd like this timeout
-// to be as small as possible (see the description in the .h file).
-//
-// Currently, |tiny_timeout()| is usually 100 ms (possibly scaled under ASAN,
-// etc.). Based on this, set it to (usually be) 30 ms on Windows and 20 ms
-// elsewhere.
-#if defined(OS_WIN) || defined(OS_ANDROID)
-  return (TinyDeadline() * 3) / 10;
-#else
-  return (TinyDeadline() * 2) / 10;
-#endif
-}
-
-MojoDeadline TinyDeadline() {
-  return static_cast<MojoDeadline>(
-      TestTimeouts::tiny_timeout().InMicroseconds());
-}
-
-MojoDeadline ActionDeadline() {
-  return static_cast<MojoDeadline>(
-      TestTimeouts::action_timeout().InMicroseconds());
-}
-
-void Sleep(MojoDeadline deadline) {
-  CHECK_LE(deadline,
-           static_cast<MojoDeadline>(std::numeric_limits<int64_t>::max()));
-  base::PlatformThread::Sleep(
-      base::TimeDelta::FromMicroseconds(static_cast<int64_t>(deadline)));
-}
-
-Stopwatch::Stopwatch() = default;
-
-Stopwatch::~Stopwatch() = default;
-
-void Stopwatch::Start() {
-  start_time_ = base::TimeTicks::Now();
-}
-
-MojoDeadline Stopwatch::Elapsed() {
-  int64_t result = (base::TimeTicks::Now() - start_time_).InMicroseconds();
-  // |DCHECK_GE|, not |CHECK_GE|, since this may be performance-important.
-  DCHECK_GE(result, 0);
-  return static_cast<MojoDeadline>(result);
-}
-
-}  // namespace test
-}  // namespace core
-}  // namespace mojo
diff --git a/chromium/mojo/core/test_utils.h b/chromium/mojo/core/test_utils.h
deleted file mode 100644
index 98ac51e182d..00000000000
--- a/chromium/mojo/core/test_utils.h
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MOJO_CORE_TEST_UTILS_H_
-#define MOJO_CORE_TEST_UTILS_H_
-
-#include "base/macros.h"
-#include "base/time/time.h"
-#include "mojo/public/c/system/types.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace mojo {
-namespace core {
-namespace test {
-
-MojoDeadline DeadlineFromMilliseconds(unsigned milliseconds);
-
-// A timeout smaller than |TestTimeouts::tiny_timeout()|, as a |MojoDeadline|.
-// Warning: This may lead to flakiness, but this is unavoidable if, e.g., you're
-// trying to ensure that functions with timeouts are reasonably accurate. We
-// want this to be as small as possible without causing too much flakiness.
-MojoDeadline EpsilonDeadline();
-
-// |TestTimeouts::tiny_timeout()|, as a |MojoDeadline|. (Expect this to be on
-// the order of 100 ms.)
-MojoDeadline TinyDeadline();
-
-// |TestTimeouts::action_timeout()|, as a |MojoDeadline|. (Expect this to be on
-// the order of 10 s.)
-MojoDeadline ActionDeadline();
-
-// Sleeps for at least the specified duration.
-void Sleep(MojoDeadline deadline);
-
-// Stopwatch -------------------------------------------------------------------
-
-// A simple "stopwatch" for measuring time elapsed from a given starting point.
-class Stopwatch {
- public:
-  Stopwatch();
-  ~Stopwatch();
-
-  void Start();
-  // Returns the amount of time elapsed since the last call to |Start()| (in
-  // microseconds).
-  MojoDeadline Elapsed();
-
- private:
-  base::TimeTicks start_time_;
-
-  DISALLOW_COPY_AND_ASSIGN(Stopwatch);
-};
-
-}  // namespace test
-}  // namespace core
-}  // namespace mojo
-
-#endif  // MOJO_CORE_TEST_UTILS_H_
diff --git a/chromium/mojo/core/trap_unittest.cc b/chromium/mojo/core/trap_unittest.cc
index 8ff1f74a6ad..65595510930 100644
--- a/chromium/mojo/core/trap_unittest.cc
+++ b/chromium/mojo/core/trap_unittest.cc
@@ -14,7 +14,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/rand_util.h"
 #include "base/synchronization/waitable_event.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/simple_thread.h"
 #include "base/time/time.h"
diff --git a/chromium/mojo/public/DEPS b/chromium/mojo/public/DEPS
index 185539038b8..8bed1ad0e7c 100644
--- a/chromium/mojo/public/DEPS
+++ b/chromium/mojo/public/DEPS
@@ -9,4 +9,5 @@ include_rules = [
 
   # Temporary until mojom [Native] is gone.
   "+ipc/ipc_param_traits.h",
+  "+third_party/perfetto/protos/perfetto/trace/track_event",
 ]
diff --git a/chromium/mojo/public/c/system/types.h b/chromium/mojo/public/c/system/types.h
index bb6504343a7..56ffd789916 100644
--- a/chromium/mojo/public/c/system/types.h
+++ b/chromium/mojo/public/c/system/types.h
@@ -124,18 +124,6 @@ const MojoResult MOJO_RESULT_SHOULD_WAIT = 17;
 #define MOJO_RESULT_SHOULD_WAIT ((MojoResult)17)
 #endif
 
-// |MojoDeadline|: Used to specify deadlines (timeouts), in microseconds (except
-// for |MOJO_DEADLINE_INDEFINITE|).
-//   |MOJO_DEADLINE_INDEFINITE| - Used to indicate "forever".
-
-typedef uint64_t MojoDeadline;
-
-#ifdef __cplusplus
-const MojoDeadline MOJO_DEADLINE_INDEFINITE = static_cast<MojoDeadline>(-1);
-#else
-#define MOJO_DEADLINE_INDEFINITE ((MojoDeadline)-1)
-#endif
-
 // Flags passed to |MojoInitialize()| via |MojoInitializeOptions|.
 typedef uint32_t MojoInitializeFlags;
 
diff --git a/chromium/mojo/public/cpp/base/BUILD.gn b/chromium/mojo/public/cpp/base/BUILD.gn
index 9aaf1e0d796..ee0eb158939 100644
--- a/chromium/mojo/public/cpp/base/BUILD.gn
+++ b/chromium/mojo/public/cpp/base/BUILD.gn
@@ -90,6 +90,8 @@ component("shared_typemap_traits") {
     "generic_pending_receiver_mojom_traits.h",
     "read_only_buffer_mojom_traits.cc",
     "read_only_buffer_mojom_traits.h",
+    "read_only_file_mojom_traits.cc",
+    "read_only_file_mojom_traits.h",
     "shared_memory_mojom_traits.cc",
     "shared_memory_mojom_traits.h",
     "time_mojom_traits.cc",
diff --git a/chromium/mojo/public/cpp/base/big_buffer.h b/chromium/mojo/public/cpp/base/big_buffer.h
index ef13e1e39b0..81d0b994d41 100644
--- a/chromium/mojo/public/cpp/base/big_buffer.h
+++ b/chromium/mojo/public/cpp/base/big_buffer.h
@@ -176,7 +176,7 @@ class COMPONENT_EXPORT(MOJO_BASE) BigBufferView {
   static BigBufferView CreateInvalidForTest();
 
  private:
-  BigBuffer::StorageType storage_type_;
+  BigBuffer::StorageType storage_type_ = BigBuffer::StorageType::kBytes;
   base::span<const uint8_t> bytes_;
   base::Optional<internal::BigBufferSharedMemoryRegion> shared_memory_;
 
diff --git a/chromium/mojo/public/cpp/base/file_unittest.cc b/chromium/mojo/public/cpp/base/file_unittest.cc
index e1db729c752..90d08eb97b2 100644
--- a/chromium/mojo/public/cpp/base/file_unittest.cc
+++ b/chromium/mojo/public/cpp/base/file_unittest.cc
@@ -3,9 +3,13 @@
 // found in the LICENSE file.
 
 #include "base/files/scoped_temp_dir.h"
+#include "base/sync_socket.h"
+#include "build/build_config.h"
 #include "mojo/public/cpp/base/file_mojom_traits.h"
+#include "mojo/public/cpp/base/read_only_file_mojom_traits.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/mojom/base/file.mojom.h"
+#include "mojo/public/mojom/base/read_only_file.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo_base {
@@ -69,5 +73,97 @@ TEST(FileTest, InvalidFile) {
   EXPECT_FALSE(file_out.IsValid());
 }
 
+TEST(FileTest, ReadOnlyFile) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+
+  base::File file(
+      temp_dir.GetPath().AppendASCII("test_file.txt"),
+      base::File::FLAG_CREATE | base::File::FLAG_WRITE | base::File::FLAG_READ);
+  const base::StringPiece test_content =
+      "A test string to be stored in a test file";
+  file.WriteAtCurrentPos(test_content.data(),
+                         base::checked_cast<int>(test_content.size()));
+  file.Close();
+
+  base::File readonly(temp_dir.GetPath().AppendASCII("test_file.txt"),
+                      base::File::FLAG_OPEN | base::File::FLAG_READ);
+
+  base::File file_out;
+  ASSERT_TRUE(mojo::test::SerializeAndDeserialize<mojom::ReadOnlyFile>(
+      &readonly, &file_out));
+  std::vector<char> content(test_content.size());
+  ASSERT_TRUE(file_out.IsValid());
+  ASSERT_FALSE(file_out.async());
+  ASSERT_EQ(static_cast<int>(test_content.size()),
+            file_out.Read(0, content.data(),
+                          base::checked_cast<int>(test_content.size())));
+  EXPECT_EQ(test_content,
+            base::StringPiece(content.data(), test_content.size()));
+}
+
+// This dies only if we can interrogate the underlying platform handle.
+#if defined(OS_WIN) || defined(OS_POSIX) || defined(OS_FUCHSIA)
+#if !defined(OS_NACL) && !defined(OS_AIX)
+TEST(FileTest, ReadOnlyFileDeath) {
+#if defined(OFFICIAL_BUILD)
+  const char kReadOnlyFileCheckFailedRegex[] = "";
+#else
+  const char kReadOnlyFileCheckFailedRegex[] = "Check failed: IsReadOnlyFile";
+#endif
+
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+
+  base::File file(
+      temp_dir.GetPath().AppendASCII("test_file.txt"),
+      base::File::FLAG_CREATE | base::File::FLAG_WRITE | base::File::FLAG_READ);
+  const base::StringPiece test_content =
+      "A test string to be stored in a test file";
+  file.WriteAtCurrentPos(test_content.data(),
+                         base::checked_cast<int>(test_content.size()));
+  file.Close();
+
+  base::File writable(
+      temp_dir.GetPath().AppendASCII("test_file.txt"),
+      base::File::FLAG_OPEN | base::File::FLAG_READ | base::File::FLAG_WRITE);
+
+  base::File file_out;
+  EXPECT_DEATH_IF_SUPPORTED(
+      mojo::test::SerializeAndDeserialize<mojom::ReadOnlyFile>(&writable,
+                                                               &file_out),
+      kReadOnlyFileCheckFailedRegex);
+}
+#endif  // !defined(OS_NACL) && !defined(OS_AIX)
+#endif  // defined(OS_WIN) || defined(OS_POSIX) || defined(OS_FUCHSIA)
+
+// This should work on all platforms. This check might be relaxed in which case
+// this test can be removed.
+#if DCHECK_IS_ON()
+TEST(FileTest, NonPhysicalFileDeath) {
+#if defined(OFFICIAL_BUILD)
+  const char kPhysicalFileCheckFailedRegex[] = "";
+#else
+  const char kPhysicalFileCheckFailedRegex[] = "Check failed: IsPhysicalFile";
+#endif
+
+  base::SyncSocket sync_a;
+  base::SyncSocket sync_b;
+  ASSERT_TRUE(base::SyncSocket::CreatePair(&sync_a, &sync_b));
+  base::File file_pipe_a(sync_a.Take());
+  base::File file_pipe_b(sync_b.Take());
+
+  base::File file_out;
+  EXPECT_DEATH_IF_SUPPORTED(
+      mojo::test::SerializeAndDeserialize<mojom::ReadOnlyFile>(&file_pipe_a,
+                                                               &file_out),
+      kPhysicalFileCheckFailedRegex);
+  EXPECT_DEATH_IF_SUPPORTED(
+      mojo::test::SerializeAndDeserialize<mojom::ReadOnlyFile>(&file_pipe_b,
+                                                               &file_out),
+      kPhysicalFileCheckFailedRegex);
+}
+#endif  // DCHECK_IS_ON()
+
 }  // namespace file_unittest
 }  // namespace mojo_base
diff --git a/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.cc b/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.cc
new file mode 100644
index 00000000000..190e659d16e
--- /dev/null
+++ b/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.cc
@@ -0,0 +1,101 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/public/cpp/base/read_only_file_mojom_traits.h"
+
+#include "base/files/file.h"
+#include "build/build_config.h"
+
+#if defined(OS_POSIX) || defined(OS_FUCHSIA)
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+#if defined(OS_WIN)
+#include <windows.h>
+#include <winternl.h>
+#endif
+
+namespace mojo {
+namespace {
+#if defined(OS_WIN)
+bool GetGrantedAccess(HANDLE handle, DWORD* flags) {
+  static const auto nt_query_object =
+      reinterpret_cast<decltype(&NtQueryObject)>(
+          GetProcAddress(GetModuleHandle(L"ntdll.dll"), "NtQueryObject"));
+  PUBLIC_OBJECT_BASIC_INFORMATION info;
+  ULONG len = sizeof(info);
+  ULONG consumed = 0;
+  auto ret =
+      nt_query_object(handle, ObjectBasicInformation, &info, len, &consumed);
+  if (ret)
+    return false;
+  *flags = info.GrantedAccess;
+  return true;
+}
+#endif  // defined(OS_WIN)
+
+// True if the underlying handle is only readable. Where possible this excludes
+// deletion, writing, truncation, append and other operations that might modify
+// the underlying file. False if we can tell that the file could be modified.
+// On platforms where we cannot test the handle, always returns true.
+bool IsReadOnlyFile(base::File& file) {
+  bool is_readonly = true;
+#if defined(OS_WIN)
+  DWORD flags = 0;
+  if (!GetGrantedAccess(file.GetPlatformFile(), &flags))
+    return false;
+
+  // Cannot use GENERIC_WRITE as that includes SYNCHRONIZE.
+  // This is ~(all the writable permissions).
+  is_readonly =
+      !(flags & (FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_DATA |
+                 FILE_WRITE_EA | WRITE_DAC | WRITE_OWNER | DELETE));
+#elif defined(OS_FUCHSIA) || \
+    (defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_AIX))
+  is_readonly =
+      (fcntl(file.GetPlatformFile(), F_GETFL) & O_ACCMODE) == O_RDONLY;
+#endif
+  return is_readonly;
+}
+
+bool IsPhysicalFile(base::File& file) {
+#if defined(OS_WIN)
+  // Verify if this is a real file (not a socket/pipe etc.).
+  DWORD type = GetFileType(file.GetPlatformFile());
+  return type == FILE_TYPE_DISK;
+#else
+  // This may block but in practice this is unlikely for already opened
+  // physical files.
+  struct stat st;
+  if (fstat(file.GetPlatformFile(), &st) != 0)
+    return false;
+  return S_ISREG(st.st_mode);
+#endif
+}
+
+}  // namespace
+
+mojo::PlatformHandle StructTraits<mojo_base::mojom::ReadOnlyFileDataView,
+                                  base::File>::fd(base::File& file) {
+  DCHECK(file.IsValid());
+  // For now we require real files as on some platforms it is too difficult to
+  // be sure that more general handles cannot be written or made writable. This
+  // could be relaxed if an interface needs readonly pipes. This check may block
+  // so cannot be enabled in release builds.
+  DCHECK(IsPhysicalFile(file));
+  CHECK(IsReadOnlyFile(file));
+
+  return mojo::PlatformHandle(
+      base::ScopedPlatformFile(file.TakePlatformFile()));
+}
+
+bool StructTraits<mojo_base::mojom::ReadOnlyFileDataView, base::File>::Read(
+    mojo_base::mojom::ReadOnlyFileDataView data,
+    base::File* file) {
+  *file = base::File(data.TakeFd().TakePlatformFile(), data.async());
+  return true;
+}
+
+}  // namespace mojo
diff --git a/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.h b/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.h
new file mode 100644
index 00000000000..025ee7f2374
--- /dev/null
+++ b/chromium/mojo/public/cpp/base/read_only_file_mojom_traits.h
@@ -0,0 +1,29 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_PUBLIC_CPP_BASE_READ_ONLY_FILE_MOJOM_TRAITS_H_
+#define MOJO_PUBLIC_CPP_BASE_READ_ONLY_FILE_MOJOM_TRAITS_H_
+
+#include "base/component_export.h"
+#include "base/files/file.h"
+#include "mojo/public/mojom/base/read_only_file.mojom-shared.h"
+
+namespace mojo {
+
+template <>
+struct COMPONENT_EXPORT(MOJO_BASE_SHARED_TRAITS)
+    StructTraits<mojo_base::mojom::ReadOnlyFileDataView, base::File> {
+  static bool IsNull(const base::File& file) { return !file.IsValid(); }
+
+  static void SetToNull(base::File* file) { *file = base::File(); }
+
+  static mojo::PlatformHandle fd(base::File& file);
+  static bool async(base::File& file) { return file.async(); }
+  static bool Read(mojo_base::mojom::ReadOnlyFileDataView data,
+                   base::File* file);
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_BASE_READ_ONLY_FILE_MOJOM_TRAITS_H_
diff --git a/chromium/mojo/public/cpp/base/values_mojom_traits.cc b/chromium/mojo/public/cpp/base/values_mojom_traits.cc
index 9a1d84c604a..69bd8167377 100644
--- a/chromium/mojo/public/cpp/base/values_mojom_traits.cc
+++ b/chromium/mojo/public/cpp/base/values_mojom_traits.cc
@@ -20,8 +20,8 @@ bool StructTraits<mojo_base::mojom::DictionaryValueDataView, base::Value>::Read(
   dict_storage.reserve(view.size());
   for (size_t i = 0; i < view.size(); ++i) {
     base::StringPiece key;
-    auto value = std::make_unique<base::Value>();
-    if (!view.keys().Read(i, &key) || !view.values().Read(i, value.get()))
+    base::Value value;
+    if (!view.keys().Read(i, &key) || !view.values().Read(i, &value))
       return false;
     dict_storage.emplace_back(key.as_string(), std::move(value));
   }
diff --git a/chromium/mojo/public/cpp/base/values_unittest.cc b/chromium/mojo/public/cpp/base/values_unittest.cc
index 75d975470bc..5624238916a 100644
--- a/chromium/mojo/public/cpp/base/values_unittest.cc
+++ b/chromium/mojo/public/cpp/base/values_unittest.cc
@@ -85,17 +85,14 @@ TEST(ValuesStructTraitsTest, DictionaryValue) {
   // move-only types and initializer lists don't mix. Initializer lists can't be
   // modified: thus it's not possible to move.
   std::vector<base::Value::DictStorage::value_type> storage;
-  storage.emplace_back("null", std::make_unique<base::Value>());
-  storage.emplace_back("bool", std::make_unique<base::Value>(false));
-  storage.emplace_back("int", std::make_unique<base::Value>(0));
-  storage.emplace_back("double", std::make_unique<base::Value>(0.0));
-  storage.emplace_back("string", std::make_unique<base::Value>("0"));
-  storage.emplace_back(
-      "binary", std::make_unique<base::Value>(base::Value::BlobStorage({0})));
-  storage.emplace_back(
-      "dictionary", std::make_unique<base::Value>(base::Value::DictStorage()));
-  storage.emplace_back(
-      "list", std::make_unique<base::Value>(base::Value::ListStorage()));
+  storage.emplace_back("null", base::Value());
+  storage.emplace_back("bool", false);
+  storage.emplace_back("int", 0);
+  storage.emplace_back("double", 0.0);
+  storage.emplace_back("string", "0");
+  storage.emplace_back("binary", base::Value::BlobStorage({0}));
+  storage.emplace_back("dictionary", base::Value::DictStorage());
+  storage.emplace_back("list", base::Value::ListStorage());
 
   base::Value in(base::Value::DictStorage(std::move(storage)));
   base::Value out;
diff --git a/chromium/mojo/public/cpp/bindings/BUILD.gn b/chromium/mojo/public/cpp/bindings/BUILD.gn
index fb725f77058..77efb306eaf 100644
--- a/chromium/mojo/public/cpp/bindings/BUILD.gn
+++ b/chromium/mojo/public/cpp/bindings/BUILD.gn
@@ -2,13 +2,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//base/trace_event/tracing.gni")
 import("//build/buildflag_header.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//tools/ipc_fuzzer/ipc_fuzzer.gni")
 
 declare_args() {
-  enable_mojo_tracing = false
+  enable_mojo_tracing = extended_tracing_enabled
 
   # enable_random_mojo_delays starts a task runner that periodically pauses
   # random Mojo bindings and later resumes them, in order to test whether parts
@@ -79,7 +80,6 @@ component("bindings_base") {
     "lib/serialization_util.h",
     "lib/string_serialization.h",
     "lib/template_util.h",
-    "lib/tracing_helper.h",
     "lib/unserialized_message_context.cc",
     "lib/unserialized_message_context.h",
     "lib/validate_params.h",
diff --git a/chromium/mojo/public/cpp/bindings/README.md b/chromium/mojo/public/cpp/bindings/README.md
index a15cf13632f..9eff612fb6e 100644
--- a/chromium/mojo/public/cpp/bindings/README.md
+++ b/chromium/mojo/public/cpp/bindings/README.md
@@ -168,7 +168,7 @@ defines a `BindNewPipeAndPassReceiver` method:
 
 ``` cpp
 mojo::Remote<sample::mojom::Logger> logger;
-auto receiver = logger.BindNewPipeAndPassReceiver());
+auto receiver = logger.BindNewPipeAndPassReceiver();
 ```
 
 This second snippet is equivalent to the first one.
diff --git a/chromium/mojo/public/cpp/bindings/associated_binding.h b/chromium/mojo/public/cpp/bindings/associated_binding.h
index a0b6eeadc21..62f12b16564 100644
--- a/chromium/mojo/public/cpp/bindings/associated_binding.h
+++ b/chromium/mojo/public/cpp/bindings/associated_binding.h
@@ -149,9 +149,29 @@ class AssociatedBinding : public AssociatedBindingBase {
     return old_impl;
   }
 
+  // Acquires a callback which may be run to report the currently dispatching
+  // message as bad and close this binding. Note that this is only legal to
+  // call from directly within stack frame of a message dispatch, but the
+  // returned callback may be called exactly once any time thereafter to report
+  // the message as bad. |GetBadMessageCallback()| may only be called once per
+  // message, and the returned callback must be run on the same sequence to
+  // which this binding is bound.
+  ReportBadMessageCallback GetBadMessageCallback() {
+    return base::BindOnce(
+        [](ReportBadMessageCallback inner_callback,
+           base::WeakPtr<AssociatedBinding> binding, const std::string& error) {
+          std::move(inner_callback).Run(error);
+          if (binding)
+            binding->Close();
+        },
+        mojo::GetBadMessageCallback(), weak_ptr_factory_.GetWeakPtr());
+  }
+
  private:
   typename Interface::template Stub_<ImplRefTraits> stub_;
 
+  base::WeakPtrFactory<AssociatedBinding> weak_ptr_factory_{this};
+
   DISALLOW_COPY_AND_ASSIGN(AssociatedBinding);
 };
 
diff --git a/chromium/mojo/public/cpp/bindings/associated_receiver.h b/chromium/mojo/public/cpp/bindings/associated_receiver.h
index f03b37dd27a..2d9ed6a09d5 100644
--- a/chromium/mojo/public/cpp/bindings/associated_receiver.h
+++ b/chromium/mojo/public/cpp/bindings/associated_receiver.h
@@ -241,6 +241,26 @@ class AssociatedReceiver {
     return binding_.SwapImplForTesting(new_impl);
   }
 
+  // Reports the currently dispatching message as bad and resets this receiver.
+  // Note that this is only legal to call from within the stack frame of a
+  // message dispatch. If you need to do asynchronous work before determining
+  // the legitimacy of a message, use GetBadMessageCallback() and retain its
+  // result until ready to invoke or discard it.
+  void ReportBadMessage(const std::string& error) {
+    GetBadMessageCallback().Run(error);
+  }
+
+  // Acquires a callback which may be run to report the currently dispatching
+  // message as bad and reset this receiver. Note that this is only legal to
+  // call from directly within stack frame of a message dispatch, but the
+  // returned callback may be called exactly once any time thereafter to report
+  // the message as bad. |GetBadMessageCallback()| may only be called once per
+  // message, and the returned callback must be run on the same sequence to
+  // which this Receiver is bound.
+  ReportBadMessageCallback GetBadMessageCallback() {
+    return binding_.GetBadMessageCallback();
+  }
+
  private:
   // TODO(https://crbug.com/875030): Move AssociatedBinding details into this
   // class.
diff --git a/chromium/mojo/public/cpp/bindings/connector.h b/chromium/mojo/public/cpp/bindings/connector.h
index 1616f1bf023..905829cdfb1 100644
--- a/chromium/mojo/public/cpp/bindings/connector.h
+++ b/chromium/mojo/public/cpp/bindings/connector.h
@@ -85,7 +85,7 @@ class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) Connector : public MessageReceiver {
   Connector(ScopedMessagePipeHandle message_pipe,
             ConnectorConfig config,
             scoped_refptr<base::SequencedTaskRunner> runner,
-            const char* heap_profiler_tag = "unknown interface");
+            const char* interface_name = "unknown interface");
   ~Connector() override;
 
   // Sets outgoing serialization mode.
@@ -306,7 +306,7 @@ class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) Connector : public MessageReceiver {
 
   // The tag used to track heap allocations that originated from a Watcher
   // notification.
-  const char* heap_profiler_tag_ = "unknown interface";
+  const char* interface_name_ = "unknown interface";
 
   // A cached pointer to the RunLoopNestingObserver for the thread on which this
   // Connector was created.
diff --git a/chromium/mojo/public/cpp/bindings/lib/connector.cc b/chromium/mojo/public/cpp/bindings/lib/connector.cc
index 93ea25007ec..2766f8d65c3 100644
--- a/chromium/mojo/public/cpp/bindings/lib/connector.cc
+++ b/chromium/mojo/public/cpp/bindings/lib/connector.cc
@@ -21,14 +21,15 @@
 #include "base/task/current_thread.h"
 #include "base/threading/sequence_local_storage_slot.h"
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/typed_macros.h"
 #include "mojo/public/c/system/quota.h"
 #include "mojo/public/cpp/bindings/features.h"
 #include "mojo/public/cpp/bindings/lib/may_auto_lock.h"
 #include "mojo/public/cpp/bindings/lib/message_quota_checker.h"
-#include "mojo/public/cpp/bindings/lib/tracing_helper.h"
 #include "mojo/public/cpp/bindings/mojo_buildflags.h"
 #include "mojo/public/cpp/bindings/sync_handle_watcher.h"
 #include "mojo/public/cpp/system/wait.h"
+#include "third_party/perfetto/protos/perfetto/trace/track_event/chrome_mojo_event_info.pbzero.h"
 
 #if defined(ENABLE_IPC_FUZZER)
 #include "mojo/public/cpp/bindings/message_dumper.h"
@@ -145,14 +146,14 @@ void Connector::ActiveDispatchTracker::NotifyBeginNesting() {
 Connector::Connector(ScopedMessagePipeHandle message_pipe,
                      ConnectorConfig config,
                      scoped_refptr<base::SequencedTaskRunner> runner,
-                     const char* heap_profiler_tag)
+                     const char* interface_name)
     : message_pipe_(std::move(message_pipe)),
       task_runner_(std::move(runner)),
       error_(false),
       force_immediate_dispatch_(!EnableTaskPerMessage()),
       outgoing_serialization_mode_(g_default_outgoing_serialization_mode),
       incoming_serialization_mode_(g_default_incoming_serialization_mode),
-      heap_profiler_tag_(heap_profiler_tag),
+      interface_name_(interface_name),
       nesting_observer_(RunLoopNestingObserver::GetForThread()) {
   if (config == MULTI_THREADED_SEND)
     lock_.emplace();
@@ -410,7 +411,7 @@ void Connector::WaitToReadMore() {
   DCHECK(task_runner_->RunsTasksInCurrentSequence());
   handle_watcher_ = std::make_unique<SimpleWatcher>(
       FROM_HERE, SimpleWatcher::ArmingPolicy::MANUAL, task_runner_,
-      heap_profiler_tag_);
+      interface_name_);
   MojoResult rv = handle_watcher_->Watch(
       message_pipe_.get(), MOJO_HANDLE_SIGNAL_READABLE,
       base::BindRepeating(&Connector::OnWatcherHandleReady,
@@ -459,11 +460,11 @@ MojoResult Connector::ReadMessage(Message* message) {
     // was a problem extracting handles from it. We treat this essentially as
     // a bad IPC because we don't really have a better option.
     //
-    // We include |heap_profiler_tag_| in the error message since it usually
+    // We include |interface_name_| in the error message since it usually
     // (via this Connector's owner) provides useful information about which
     // binding interface is using this Connector.
     NotifyBadMessage(handle.get(),
-                     std::string(heap_profiler_tag_) +
+                     std::string(interface_name_) +
                          "One or more handle attachments were invalid.");
     return MOJO_RESULT_ABORTED;
   }
@@ -490,11 +491,15 @@ bool Connector::DispatchMessage(Message message) {
   }
 
   TRACE_EVENT_WITH_FLOW0("toplevel.flow", "mojo::Message Receive",
-                         MANGLE_MESSAGE_ID(message.header()->trace_id),
-                         TRACE_EVENT_FLAG_FLOW_IN);
+                         message.header()->trace_id, TRACE_EVENT_FLAG_FLOW_IN);
 #if !BUILDFLAG(MOJO_TRACE_ENABLED)
   // This emits just full class name, and is inferior to mojo tracing.
-  TRACE_EVENT0("mojom", heap_profiler_tag_);
+  TRACE_EVENT("toplevel", "Connector::DispatchMessage",
+              [this](perfetto::EventContext ctx) {
+                ctx.event()
+                    ->set_chrome_mojo_event_info()
+                    ->set_watcher_notify_interface_tag(interface_name_);
+              });
 #endif
 
   if (connection_group_)
diff --git a/chromium/mojo/public/cpp/bindings/lib/message.cc b/chromium/mojo/public/cpp/bindings/lib/message.cc
index 8c489947606..d5403f933ce 100644
--- a/chromium/mojo/public/cpp/bindings/lib/message.cc
+++ b/chromium/mojo/public/cpp/bindings/lib/message.cc
@@ -20,9 +20,9 @@
 #include "base/strings/stringprintf.h"
 #include "base/threading/sequence_local_storage_slot.h"
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/trace_id_helper.h"
 #include "mojo/public/cpp/bindings/associated_group_controller.h"
 #include "mojo/public/cpp/bindings/lib/array_internal.h"
-#include "mojo/public/cpp/bindings/lib/tracing_helper.h"
 #include "mojo/public/cpp/bindings/lib/unserialized_message_context.h"
 
 namespace mojo {
@@ -47,19 +47,6 @@ void AllocateHeaderFromBuffer(internal::Buffer* buffer, HeaderType** header) {
   (*header)->num_bytes = sizeof(HeaderType);
 }
 
-uint32_t GetTraceId(void* object) {
-  // |object| is a pointer to some object, which we are going to use as
-  // a hopefully unique id for this message.
-  // Additionally xor it with a counter to protect against the situations when
-  // a new object is allocated with the same address.
-  // The counter alone is not sufficient because we also have to deal with
-  // different processes, and the counter is only process-unique.
-  static std::atomic<int> counter{0};
-  uint64_t value = reinterpret_cast<intptr_t>(object);
-  return static_cast<uint32_t>(counter.fetch_add(1, std::memory_order_relaxed) ^
-                               (value >> 32) ^ ((value << 32) >> 32));
-}
-
 void WriteMessageHeader(uint32_t name,
                         uint32_t flags,
                         uint32_t trace_id,
@@ -96,15 +83,15 @@ void WriteMessageHeader(uint32_t name,
 
 void CreateSerializedMessageObject(uint32_t name,
                                    uint32_t flags,
-                                   uint32_t trace_id,
                                    size_t payload_size,
                                    size_t payload_interface_id_count,
                                    MojoCreateMessageFlags create_message_flags,
                                    std::vector<ScopedHandle>* handles,
                                    ScopedMessageHandle* out_handle,
                                    internal::Buffer* out_buffer) {
-  TRACE_EVENT_WITH_FLOW0("toplevel.flow", "mojo::Message Send",
-                         MANGLE_MESSAGE_ID(trace_id),
+  uint32_t trace_id =
+      static_cast<uint32_t>(base::trace_event::GetNextGlobalTraceId());
+  TRACE_EVENT_WITH_FLOW0("toplevel.flow", "mojo::Message Send", trace_id,
                          TRACE_EVENT_FLAG_FLOW_OUT);
 
   ScopedMessageHandle handle;
@@ -147,10 +134,10 @@ void SerializeUnserializedContext(MojoMessageHandle message,
                                   uintptr_t context_value) {
   auto* context =
       reinterpret_cast<internal::UnserializedMessageContext*>(context_value);
-  uint32_t trace_id = GetTraceId(context);
+  uint32_t trace_id =
+      static_cast<uint32_t>(base::trace_event::GetNextGlobalTraceId());
 
-  TRACE_EVENT_WITH_FLOW0("toplevel.flow", "mojo::Message Send",
-                         MANGLE_MESSAGE_ID(trace_id),
+  TRACE_EVENT_WITH_FLOW0("toplevel.flow", "mojo::Message Send", trace_id,
                          TRACE_EVENT_FLAG_FLOW_OUT);
 
   void* buffer;
@@ -244,7 +231,7 @@ Message::Message(uint32_t name,
                  MojoCreateMessageFlags create_message_flags,
                  std::vector<ScopedHandle>* handles) {
   CreateSerializedMessageObject(
-      name, flags, GetTraceId(this), payload_size, payload_interface_id_count,
+      name, flags, payload_size, payload_interface_id_count,
       create_message_flags, handles, &handle_, &payload_buffer_);
   transferable_ = true;
   serialized_ = true;
diff --git a/chromium/mojo/public/cpp/bindings/lib/serialization.h b/chromium/mojo/public/cpp/bindings/lib/serialization.h
index 1f5d7de89b5..7927d1d4092 100644
--- a/chromium/mojo/public/cpp/bindings/lib/serialization.h
+++ b/chromium/mojo/public/cpp/bindings/lib/serialization.h
@@ -63,7 +63,11 @@ struct MojomSerializationImplTraits<
 template <typename MojomType, typename UserType>
 mojo::Message SerializeAsMessageImpl(UserType* input) {
   SerializationContext context;
-  mojo::Message message(0, 0, 0, 0, nullptr);
+  // Note that this is only called by application code serializing a structure
+  // manually (e.g. for storage). As such we don't want Mojo's soft message size
+  // limits to be applied.
+  mojo::Message message(0, 0, 0, 0, MOJO_CREATE_MESSAGE_FLAG_UNLIMITED_SIZE,
+                        nullptr);
   typename MojomTypeTraits<MojomType>::Data::BufferWriter writer;
   MojomSerializationImplTraits<MojomType>::Serialize(
       *input, message.payload_buffer(), &writer, &context);
diff --git a/chromium/mojo/public/cpp/bindings/lib/tracing_helper.h b/chromium/mojo/public/cpp/bindings/lib/tracing_helper.h
deleted file mode 100644
index ebc5cc27e85..00000000000
--- a/chromium/mojo/public/cpp/bindings/lib/tracing_helper.h
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_TRACING_HELPER_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_TRACING_HELPER_H_
-
-#define MANGLE_MESSAGE_ID(id) (id ^ ::mojo::internal::kMojoMessageMangleMask)
-
-namespace mojo {
-namespace internal {
-
-// Mojo message id is 32-bit, but for tracing we ensure that mojo messages
-// don't collide with other trace events.
-constexpr uint64_t kMojoMessageMangleMask = 0x655b2a8e8efdf27f;
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_TRACING_HELPER_H_
diff --git a/chromium/mojo/public/cpp/bindings/pending_receiver.h b/chromium/mojo/public/cpp/bindings/pending_receiver.h
index 07d300f424e..1df56ce9278 100644
--- a/chromium/mojo/public/cpp/bindings/pending_receiver.h
+++ b/chromium/mojo/public/cpp/bindings/pending_receiver.h
@@ -74,7 +74,7 @@ class PendingReceiver {
                                      Interface>)(T&&)>>::value>* = nullptr>
   PendingReceiver(T&& other)
       : PendingReceiver(PendingReceiverConverter<T>::template To<Interface>(
-            std::move(other))) {}
+            std::forward<T>(other))) {}
 #endif  // !defined(OS_NACL)
 
   ~PendingReceiver() = default;
diff --git a/chromium/mojo/public/cpp/bindings/receiver.h b/chromium/mojo/public/cpp/bindings/receiver.h
index 6f8b9976581..e1357f64fa2 100644
--- a/chromium/mojo/public/cpp/bindings/receiver.h
+++ b/chromium/mojo/public/cpp/bindings/receiver.h
@@ -185,9 +185,9 @@ class Receiver {
   }
 
   // Sets the message filter to be notified of each incoming message before
-  // dispatch. If a filter returns |false| from Accept(), the message is not
-  // dispatched and the pipe is closed. Filters cannot be removed once added
-  // and only one can be set.
+  // dispatch. If a filter returns |false| from WillDispatch(), the message is
+  // not dispatched and the pipe is closed. Filters cannot be removed once
+  // added and only one can be set.
   void SetFilter(std::unique_ptr<MessageFilter> filter) {
     DCHECK(is_bound());
     internal_state_.SetFilter(std::move(filter));
diff --git a/chromium/mojo/public/cpp/bindings/service_factory.cc b/chromium/mojo/public/cpp/bindings/service_factory.cc
index 18f12eb3490..b083ac15839 100644
--- a/chromium/mojo/public/cpp/bindings/service_factory.cc
+++ b/chromium/mojo/public/cpp/bindings/service_factory.cc
@@ -5,33 +5,44 @@
 #include "mojo/public/cpp/bindings/service_factory.h"
 
 #include "base/bind.h"
+#include "base/stl_util.h"
 
 namespace mojo {
 
+ServiceFactory::ServiceFactory() = default;
+
 ServiceFactory::~ServiceFactory() = default;
 
-bool ServiceFactory::MaybeRunService(mojo::GenericPendingReceiver* receiver) {
-  DCHECK(receiver->is_valid());
+bool ServiceFactory::CanRunService(
+    const GenericPendingReceiver& receiver) const {
+  DCHECK(receiver.is_valid());
+  return base::Contains(constructors_, *receiver.interface_name());
+}
+
+bool ServiceFactory::RunService(GenericPendingReceiver receiver,
+                                base::OnceClosure termination_callback) {
+  DCHECK(receiver.is_valid());
 
   // We grab a weak handle to the receiver's message pipe first. If any function
   // accepts the receiver, we will tie its returned object's lifetime to the
   // connection state of that pipe.
-  MessagePipeHandle pipe = receiver->pipe();
-
-  for (const auto& callback : callbacks_) {
-    if (auto instance = callback.Run(receiver)) {
-      DCHECK(!receiver->is_valid());
-      instance->WatchPipe(
-          pipe, base::BindOnce(&ServiceFactory::OnInstanceDisconnected,
-                               weak_ptr_factory_.GetWeakPtr(), instance.get()));
-      instances_.insert(std::move(instance));
-      return true;
-    }
-
-    DCHECK(receiver->is_valid());
-  }
+  MessagePipeHandle pipe = receiver.pipe();
 
-  return false;
+  auto it = constructors_.find(*receiver.interface_name());
+  if (it == constructors_.end())
+    return false;
+
+  auto instance = it->second.Run(std::move(receiver));
+  auto disconnect_callback =
+      base::BindOnce(&ServiceFactory::OnInstanceDisconnected,
+                     weak_ptr_factory_.GetWeakPtr(), instance.get());
+  if (termination_callback) {
+    disconnect_callback =
+        std::move(disconnect_callback).Then(std::move(termination_callback));
+  }
+  instance->WatchPipe(pipe, std::move(disconnect_callback));
+  instances_.insert(std::move(instance));
+  return true;
 }
 
 void ServiceFactory::OnInstanceDisconnected(InstanceHolderBase* instance) {
@@ -48,21 +59,26 @@ void ServiceFactory::InstanceHolderBase::WatchPipe(
     base::OnceClosure disconnect_callback) {
   DCHECK(!disconnect_callback_);
   disconnect_callback_ = std::move(disconnect_callback);
-  watcher_.Watch(pipe, MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+  watcher_.Watch(pipe, MOJO_HANDLE_SIGNAL_READABLE,
                  MOJO_TRIGGER_CONDITION_SIGNALS_SATISFIED,
-                 base::BindRepeating(&InstanceHolderBase::OnDisconnect,
+                 base::BindRepeating(&InstanceHolderBase::OnPipeSignaled,
                                      base::Unretained(this)));
 }
 
-void ServiceFactory::InstanceHolderBase::OnDisconnect(
+void ServiceFactory::InstanceHolderBase::OnPipeSignaled(
     MojoResult result,
     const HandleSignalsState& state) {
-  // It doesn't matter what the parameters are, since the only way the watcher
-  // can signal is if the peer was closed or the local pipe handle was closed.
-  // The callback always destroys |this| when run, so there's also no chance of
-  // this method running more than once.
-  DCHECK(disconnect_callback_);
-  std::move(disconnect_callback_).Run();
+  // We only care about the two conditions below. FAILED_PRECONDITION implies
+  // that the peer was closed and all its sent messages have been read (and
+  // dispatched) locally, while CANCELLED implies that the service pipe was
+  // closed locally. In both cases, we run the callback which will delete
+  // `this` and, ultimately, the service instance itself.
+  if (result == MOJO_RESULT_FAILED_PRECONDITION ||
+      result == MOJO_RESULT_CANCELLED) {
+    watcher_.Cancel();
+    DCHECK(disconnect_callback_);
+    std::move(disconnect_callback_).Run();
+  }
 }
 
 }  // namespace mojo
diff --git a/chromium/mojo/public/cpp/bindings/service_factory.h b/chromium/mojo/public/cpp/bindings/service_factory.h
index e31441389cd..baaf683056b 100644
--- a/chromium/mojo/public/cpp/bindings/service_factory.h
+++ b/chromium/mojo/public/cpp/bindings/service_factory.h
@@ -5,6 +5,7 @@
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_SERVICE_FACTORY_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_SERVICE_FACTORY_H_
 
+#include <map>
 #include <memory>
 
 #include "base/bind.h"
@@ -35,11 +36,11 @@ struct ServiceFactoryTraits;
 // where |T| is any type (generally an implementation of |Interface|), and
 // |Interface| is a mojom interface.
 //
-// Any time |MaybeRunService()| is called on the ServiceFactory, it will match
-// the GenericPendingReceiver argument's interface type against the list of
-// factories it has available, and if it finds a match it will run that function
-// and retain ownership of the returned object until the corresponding receiver
-// is disconnected.
+// Any time |RunService()| is called on the ServiceFactory, it will match the
+// GenericPendingReceiver argument's interface type against the list of
+// factories it has available and run the corresponding function, retaining
+// ownership of the returned object until the corresponding receiver is
+// disconnected.
 //
 // Typical usage might look something like:
 //
@@ -51,31 +52,54 @@ struct ServiceFactoryTraits;
 //       return std::make_unique<bar::BarImpl>(std::move(receiver));
 //     }
 //
-//     void HandleServiceRequest(mojo::GenericPendingReceiver receiver) {
-//       static base::NoDestructor<mojo::ServiceFactory> factory{
-//         RunFooService,
-//         RunBarService,
-//       };
+//     void RegisterServices(mojo::ServiceFactory& services) {
+//       services.Add(RunFooService);
+//       services.Add(RunBarService);
+//     }
 //
-//       if (!factory->MaybeRunService(&receiver)) {
-//         // The receiver was for neither the Foo nor Bar service. Sad!
-//         LOG(ERROR) << "Unknown service: " << *receiver.interface_name();
+//     void HandleServiceRequest(const mojo::ServiceFactory& factory,
+//                               mojo::GenericPendingReceiver receiver) {
+//       if (factory.CanRunService(receiver)) {
+//         factory.RunService(std::move(receiver), base::NullCallback());
+//         return;
 //       }
+//
+//       // The receiver was for neither the Foo nor Bar service. Sad!
+//       LOG(ERROR) << "Unknown service: " << *receiver.interface_name();
 //     }
 //
 class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) ServiceFactory {
  public:
-  template <typename... Funcs>
-  explicit ServiceFactory(Funcs... fns)
-      : callbacks_({base::BindRepeating(&RunFunction<Funcs>, fns)...}) {}
+  ServiceFactory();
   ~ServiceFactory();
 
-  // Attempts to run a service supported by this factory.
+  // Adds a new service to the factory. The argument may be any function that
+  // accepts a single PendingReceiver<T> and returns a unique_ptr<T>, where T is
+  // a service interface (that is, a generated mojom interface class
+  // corresponding to some service's main interface.)
+  template <typename Func>
+  void Add(Func func) {
+    using Interface = typename internal::ServiceFactoryTraits<Func>::Interface;
+    constructors_[Interface::Name_] =
+        base::BindRepeating(&RunConstructor<Func>, func);
+  }
+
+  // If `receiver` is references an interface matching a service known to this
+  // factory, this returns true. Otherwise it returns false. `receiver` MUST be
+  // valid.
+  bool CanRunService(const GenericPendingReceiver& receiver) const;
+
+  // Consumes `receiver` and binds it to a new instance of the corresponding
+  // service, constructed using the service's registered function within this
+  // factory.
+  //
+  // `termination_callback`, if not null, will be invoked on the calling
+  // TaskRunner whenever the new service instance is eventually destroyed.
   //
-  // Returns |true| and consumes |*receiver| if it is a suitable match for some
-  // function known by the factory; otherwise returns |false| and leaves
-  // |*receiver| intact.
-  bool MaybeRunService(GenericPendingReceiver* receiver);
+  // If the service represented by `receiver` is not known to this factory, it
+  // is discarded and `termination_callback` is never run.
+  bool RunService(GenericPendingReceiver receiver,
+                  base::OnceClosure termination_callback);
 
  private:
   class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) InstanceHolderBase {
@@ -87,7 +111,7 @@ class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) ServiceFactory {
                    base::OnceClosure disconnect_callback);
 
    private:
-    void OnDisconnect(MojoResult result, const HandleSignalsState& state);
+    void OnPipeSignaled(MojoResult result, const HandleSignalsState& state);
 
     SimpleWatcher watcher_;
     base::OnceClosure disconnect_callback_;
@@ -109,23 +133,20 @@ class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) ServiceFactory {
   };
 
   template <typename Func>
-  static std::unique_ptr<InstanceHolderBase> RunFunction(
+  static std::unique_ptr<InstanceHolderBase> RunConstructor(
       Func fn,
-      GenericPendingReceiver* receiver) {
+      GenericPendingReceiver receiver) {
     using Interface = typename internal::ServiceFactoryTraits<Func>::Interface;
-    if (auto typed_receiver = receiver->As<Interface>()) {
-      return std::make_unique<InstanceHolder<Interface>>(
-          fn(std::move(typed_receiver)));
-    }
-    return nullptr;
+    return std::make_unique<InstanceHolder<Interface>>(
+        fn(receiver.As<Interface>()));
   }
 
   void OnInstanceDisconnected(InstanceHolderBase* instance);
 
-  using GenericCallback =
+  using Constructor =
       base::RepeatingCallback<std::unique_ptr<InstanceHolderBase>(
-          GenericPendingReceiver*)>;
-  const std::vector<GenericCallback> callbacks_;
+          GenericPendingReceiver)>;
+  std::map<std::string, Constructor> constructors_;
 
   base::flat_set<std::unique_ptr<InstanceHolderBase>, base::UniquePtrComparator>
       instances_;
diff --git a/chromium/mojo/public/cpp/bindings/struct_ptr.h b/chromium/mojo/public/cpp/bindings/struct_ptr.h
index e76c34188dd..af192d33831 100644
--- a/chromium/mojo/public/cpp/bindings/struct_ptr.h
+++ b/chromium/mojo/public/cpp/bindings/struct_ptr.h
@@ -171,7 +171,11 @@ class InlinedStructPtr {
     DCHECK(state_ == VALID);
     return &value_;
   }
-  Struct* get() const { return &value_; }
+  Struct* get() const {
+    if (state_ == NIL)
+      return nullptr;
+    return &value_;
+  }
 
   void Swap(InlinedStructPtr* other) {
     std::swap(value_, other->value_);
diff --git a/chromium/mojo/public/cpp/bindings/tests/BUILD.gn b/chromium/mojo/public/cpp/bindings/tests/BUILD.gn
index fec6e6b0441..459a4dc4f79 100644
--- a/chromium/mojo/public/cpp/bindings/tests/BUILD.gn
+++ b/chromium/mojo/public/cpp/bindings/tests/BUILD.gn
@@ -28,6 +28,7 @@ source_set("tests") {
     "handle_passing_unittest.cc",
     "hash_unittest.cc",
     "idle_tracking_unittest.cc",
+    "interface_unittest.cc",
     "lazy_serialization_unittest.cc",
     "map_unittest.cc",
     "message_queue.cc",
@@ -154,6 +155,7 @@ mojom("test_mojom") {
     "enum_headers_unittest.test-mojom",
     "flush_async_unittest.test-mojom",
     "idle_tracking_unittest.test-mojom",
+    "interface_unittest.test-mojom",
     "receiver_unittest.test-mojom",
     "remote_unittest.test-mojom",
     "service_factory_unittest.test-mojom",
diff --git a/chromium/mojo/public/cpp/bindings/thread_safe_interface_ptr.h b/chromium/mojo/public/cpp/bindings/thread_safe_interface_ptr.h
index 592e83c0e2b..2fe3211b64a 100644
--- a/chromium/mojo/public/cpp/bindings/thread_safe_interface_ptr.h
+++ b/chromium/mojo/public/cpp/bindings/thread_safe_interface_ptr.h
@@ -9,7 +9,7 @@
 #include <utility>
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_runner.h"
diff --git a/chromium/mojo/public/cpp/platform/BUILD.gn b/chromium/mojo/public/cpp/platform/BUILD.gn
index 9f17405f4bf..6cd7355222f 100644
--- a/chromium/mojo/public/cpp/platform/BUILD.gn
+++ b/chromium/mojo/public/cpp/platform/BUILD.gn
@@ -4,13 +4,6 @@
 
 import("//build/config/nacl/config.gni")
 
-# This file depends on the legacy global sources assignment filter. It should
-# be converted to check target platform before assigning source files to the
-# sources variable. Remove this import and set_sources_assignment_filter call
-# when the file has been converted. See https://crbug.com/1018739 for details.
-import("//build/config/deprecated_default_sources_assignment_filter.gni")
-set_sources_assignment_filter(deprecated_default_sources_assignment_filter)
-
 component("platform") {
   output_name = "mojo_cpp_platform"
 
@@ -22,7 +15,6 @@ component("platform") {
   ]
 
   sources = [
-    "named_platform_channel_win.cc",
     "platform_channel.cc",
     "platform_channel_endpoint.cc",
     "platform_channel_server_endpoint.cc",
@@ -47,14 +39,16 @@ component("platform") {
     sources += [ "named_platform_channel_mac.cc" ]
   }
 
+  if (is_win) {
+    sources += [ "named_platform_channel_win.cc" ]
+  }
+
   if (is_fuchsia) {
     public_deps += [
       "//third_party/fuchsia-sdk/sdk/pkg/fdio",
       "//third_party/fuchsia-sdk/sdk/pkg/zx",
     ]
-  }
-
-  if (!is_fuchsia) {
+  } else {
     sources += [ "named_platform_channel.cc" ]
     public += [ "named_platform_channel.h" ]
   }
diff --git a/chromium/mojo/public/cpp/system/platform_handle.cc b/chromium/mojo/public/cpp/system/platform_handle.cc
index 64c50bb2cb8..3b04fd7a28c 100644
--- a/chromium/mojo/public/cpp/system/platform_handle.cc
+++ b/chromium/mojo/public/cpp/system/platform_handle.cc
@@ -14,19 +14,20 @@ namespace mojo {
 
 namespace {
 
-uint64_t PlatformHandleValueFromPlatformFile(base::PlatformFile file) {
+uint64_t ReleasePlatformHandleValueFromPlatformFile(
+    base::ScopedPlatformFile file) {
 #if defined(OS_WIN)
-  return reinterpret_cast<uint64_t>(file);
+  return reinterpret_cast<uint64_t>(file.Take());
 #else
-  return static_cast<uint64_t>(file);
+  return static_cast<uint64_t>(file.release());
 #endif
 }
 
-base::PlatformFile PlatformFileFromPlatformHandleValue(uint64_t value) {
+base::ScopedPlatformFile PlatformFileFromPlatformHandleValue(uint64_t value) {
 #if defined(OS_WIN)
-  return reinterpret_cast<base::PlatformFile>(value);
+  return base::ScopedPlatformFile(reinterpret_cast<base::PlatformFile>(value));
 #else
-  return static_cast<base::PlatformFile>(value);
+  return base::ScopedPlatformFile(static_cast<base::PlatformFile>(value));
 #endif
 }
 
@@ -198,12 +199,12 @@ PlatformHandle UnwrapPlatformHandle(ScopedHandle handle) {
   return PlatformHandle::FromMojoPlatformHandle(&platform_handle);
 }
 
-// Wraps a PlatformFile as a Mojo handle. Takes ownership of the file object.
-ScopedHandle WrapPlatformFile(base::PlatformFile platform_file) {
+ScopedHandle WrapPlatformFile(base::ScopedPlatformFile platform_file) {
   MojoPlatformHandle platform_handle;
   platform_handle.struct_size = sizeof(MojoPlatformHandle);
   platform_handle.type = kPlatformFileHandleType;
-  platform_handle.value = PlatformHandleValueFromPlatformFile(platform_file);
+  platform_handle.value =
+      ReleasePlatformHandleValueFromPlatformFile(std::move(platform_file));
 
   MojoHandle mojo_handle;
   MojoResult result =
@@ -213,7 +214,8 @@ ScopedHandle WrapPlatformFile(base::PlatformFile platform_file) {
   return ScopedHandle(Handle(mojo_handle));
 }
 
-MojoResult UnwrapPlatformFile(ScopedHandle handle, base::PlatformFile* file) {
+MojoResult UnwrapPlatformFile(ScopedHandle handle,
+                              base::ScopedPlatformFile* file) {
   MojoPlatformHandle platform_handle;
   platform_handle.struct_size = sizeof(MojoPlatformHandle);
   MojoResult result = MojoUnwrapPlatformHandle(handle.release().value(),
@@ -222,7 +224,7 @@ MojoResult UnwrapPlatformFile(ScopedHandle handle, base::PlatformFile* file) {
     return result;
 
   if (platform_handle.type == MOJO_PLATFORM_HANDLE_TYPE_INVALID) {
-    *file = base::kInvalidPlatformFile;
+    *file = base::ScopedPlatformFile();
   } else {
     CHECK_EQ(platform_handle.type, kPlatformFileHandleType);
     *file = PlatformFileFromPlatformHandleValue(platform_handle.value);
diff --git a/chromium/mojo/public/cpp/system/platform_handle.h b/chromium/mojo/public/cpp/system/platform_handle.h
index 106a8527254..676906ce5fa 100644
--- a/chromium/mojo/public/cpp/system/platform_handle.h
+++ b/chromium/mojo/public/cpp/system/platform_handle.h
@@ -13,7 +13,6 @@
 
 #include <stdint.h>
 
-#include "base/compiler_specific.h"
 #include "base/files/platform_file.h"
 #include "base/macros.h"
 #include "base/memory/read_only_shared_memory_region.h"
@@ -27,53 +26,16 @@
 #include "mojo/public/cpp/system/handle.h"
 #include "mojo/public/cpp/system/system_export.h"
 
-#if defined(OS_WIN)
-#include <windows.h>
-#endif
-
 namespace mojo {
 
 #if defined(OS_WIN)
 const MojoPlatformHandleType kPlatformFileHandleType =
     MOJO_PLATFORM_HANDLE_TYPE_WINDOWS_HANDLE;
-
-const MojoPlatformHandleType kPlatformSharedBufferHandleType =
-    MOJO_PLATFORM_HANDLE_TYPE_WINDOWS_HANDLE;
-
-#elif defined(OS_FUCHSIA)
-const MojoPlatformHandleType kPlatformFileHandleType =
-    MOJO_PLATFORM_HANDLE_TYPE_FILE_DESCRIPTOR;
-const MojoPlatformHandleType kPlatformSharedBufferHandleType =
-    MOJO_PLATFORM_HANDLE_TYPE_FUCHSIA_HANDLE;
-
-#elif defined(OS_POSIX)
-const MojoPlatformHandleType kPlatformFileHandleType =
-    MOJO_PLATFORM_HANDLE_TYPE_FILE_DESCRIPTOR;
-
-#if defined(OS_MAC)
-const MojoPlatformHandleType kPlatformSharedBufferHandleType =
-    MOJO_PLATFORM_HANDLE_TYPE_MACH_PORT;
 #else
-const MojoPlatformHandleType kPlatformSharedBufferHandleType =
+const MojoPlatformHandleType kPlatformFileHandleType =
     MOJO_PLATFORM_HANDLE_TYPE_FILE_DESCRIPTOR;
-#endif  // defined(OS_MAC)
-
 #endif  // defined(OS_WIN)
 
-// Used to specify the protection status of a base::SharedMemoryHandle memory
-// handle wrapped or unwrapped by mojo::WrapSharedMemoryHandle or
-// mojo::UnwrapSharedMemoryHandle below. See those functions for additional
-// details.
-enum class UnwrappedSharedMemoryHandleProtection {
-  // Indicates that the base::SharedMemoryHandle supports being mapped to
-  // writable memory regions.
-  kReadWrite,
-
-  // Indicates that the base::SharedMemoryHandle supports being mapped only to
-  // read-only memory regions.
-  kReadOnly,
-};
-
 // Wraps and unwraps base::subtle::PlatformSharedMemoryRegions. This should be
 // used only while transitioning from the legacy shared memory API. In new code
 // only base::*SharedMemoryRegion should be used instead.
@@ -90,14 +52,15 @@ MOJO_CPP_SYSTEM_EXPORT ScopedHandle WrapPlatformHandle(PlatformHandle handle);
 // support library.
 MOJO_CPP_SYSTEM_EXPORT PlatformHandle UnwrapPlatformHandle(ScopedHandle handle);
 
-// Wraps a PlatformFile as a Mojo handle. Takes ownership of the file object.
-// If |platform_file| is valid, this will return a valid handle.
+// Wraps a ScopedPlatformFile as a Mojo handle. Takes ownership of the file
+// object. If |platform_file| is valid, this will return a valid handle.
 MOJO_CPP_SYSTEM_EXPORT
-ScopedHandle WrapPlatformFile(base::PlatformFile platform_file);
+ScopedHandle WrapPlatformFile(base::ScopedPlatformFile platform_file);
 
 // Unwraps a PlatformFile from a Mojo handle.
 MOJO_CPP_SYSTEM_EXPORT
-MojoResult UnwrapPlatformFile(ScopedHandle handle, base::PlatformFile* file);
+MojoResult UnwrapPlatformFile(ScopedHandle handle,
+                              base::ScopedPlatformFile* file);
 
 // Helpers for wrapping and unwrapping new base shared memory API primitives.
 // If the input |region| is valid for the Wrap* functions, they will always
diff --git a/chromium/mojo/public/cpp/system/simple_watcher.cc b/chromium/mojo/public/cpp/system/simple_watcher.cc
index f34b90e05fb..700fda474bf 100644
--- a/chromium/mojo/public/cpp/system/simple_watcher.cc
+++ b/chromium/mojo/public/cpp/system/simple_watcher.cc
@@ -13,7 +13,9 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/heap_profiler.h"
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/typed_macros.h"
 #include "mojo/public/c/system/trap.h"
+#include "third_party/perfetto/protos/perfetto/trace/track_event/chrome_mojo_event_info.pbzero.h"
 
 namespace mojo {
 
@@ -32,9 +34,9 @@ class SimpleWatcher::Context : public base::RefCountedThreadSafe<Context> {
       MojoTriggerCondition condition,
       int watch_id,
       MojoResult* result,
-      const char* heap_profiler_tag) {
+      const char* handler_tag) {
     scoped_refptr<Context> context =
-        new Context(watcher, task_runner, watch_id, heap_profiler_tag);
+        new Context(watcher, task_runner, watch_id, handler_tag);
 
     // If MojoAddTrigger succeeds, it effectively assumes ownership of a
     // reference to |context|. In that case, this reference is balanced in
@@ -70,11 +72,11 @@ class SimpleWatcher::Context : public base::RefCountedThreadSafe<Context> {
   Context(base::WeakPtr<SimpleWatcher> weak_watcher,
           scoped_refptr<base::SequencedTaskRunner> task_runner,
           int watch_id,
-          const char* heap_profiler_tag)
+          const char* handler_tag)
       : weak_watcher_(weak_watcher),
         task_runner_(task_runner),
         watch_id_(watch_id),
-        heap_profiler_tag_(heap_profiler_tag) {}
+        handler_tag_(handler_tag) {}
 
   ~Context() = default;
 
@@ -92,10 +94,8 @@ class SimpleWatcher::Context : public base::RefCountedThreadSafe<Context> {
       weak_watcher_->OnHandleReady(watch_id_, result, state);
     } else {
       {
-        // Annotate the posted task with |heap_profiler_tag_| as the IPC
-        // interface.
-        base::TaskAnnotator::ScopedSetIpcHash scoped_set_ipc_hash(
-            heap_profiler_tag_);
+        // Annotate the posted task with |handler_tag_| as the IPC interface.
+        base::TaskAnnotator::ScopedSetIpcHash scoped_set_ipc_hash(handler_tag_);
         task_runner_->PostTask(
             FROM_HERE, base::BindOnce(&SimpleWatcher::OnHandleReady,
                                       weak_watcher_, watch_id_, result, state));
@@ -106,7 +106,7 @@ class SimpleWatcher::Context : public base::RefCountedThreadSafe<Context> {
   const base::WeakPtr<SimpleWatcher> weak_watcher_;
   const scoped_refptr<base::SequencedTaskRunner> task_runner_;
   const int watch_id_;
-  const char* heap_profiler_tag_ = nullptr;
+  const char* handler_tag_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
@@ -114,14 +114,13 @@ class SimpleWatcher::Context : public base::RefCountedThreadSafe<Context> {
 SimpleWatcher::SimpleWatcher(const base::Location& from_here,
                              ArmingPolicy arming_policy,
                              scoped_refptr<base::SequencedTaskRunner> runner,
-                             const char* heap_profiler_tag)
+                             const char* handler_tag)
     : arming_policy_(arming_policy),
       task_runner_(std::move(runner)),
       is_default_task_runner_(base::ThreadTaskRunnerHandle::IsSet() &&
                               task_runner_ ==
                                   base::ThreadTaskRunnerHandle::Get()),
-      heap_profiler_tag_(heap_profiler_tag ? heap_profiler_tag
-                                           : from_here.file_name()) {
+      handler_tag_(handler_tag ? handler_tag : from_here.file_name()) {
   MojoResult rv = CreateTrap(&Context::CallNotify, &trap_handle_);
   DCHECK_EQ(MOJO_RESULT_OK, rv);
   DCHECK(task_runner_->RunsTasksInCurrentSequence());
@@ -152,7 +151,7 @@ MojoResult SimpleWatcher::Watch(Handle handle,
   MojoResult result = MOJO_RESULT_UNKNOWN;
   context_ = Context::Create(weak_factory_.GetWeakPtr(), task_runner_,
                              trap_handle_.get(), handle_, signals, condition,
-                             watch_id_, &result, heap_profiler_tag_);
+                             watch_id_, &result, handler_tag_);
   if (!context_) {
     handle_.set_value(kInvalidHandleValue);
     callback_.Reset();
@@ -225,14 +224,17 @@ void SimpleWatcher::ArmOrNotify() {
   MojoResult ready_result;
   HandleSignalsState ready_state;
   MojoResult rv = Arm(&ready_result, &ready_state);
-  if (rv == MOJO_RESULT_OK)
+
+  // NOTE: If the watched handle has been closed, the above call will result in
+  // MOJO_RESULT_NOT_FOUND. A MOJO_RESULT_CANCELLED notification will already
+  // have been posted to this object as a result, so there's nothing else to do.
+  if (rv == MOJO_RESULT_OK || rv == MOJO_RESULT_NOT_FOUND)
     return;
 
   DCHECK_EQ(MOJO_RESULT_FAILED_PRECONDITION, rv);
   {
-    // Annotate the posted task with |heap_profiler_tag_| as the IPC interface.
-    base::TaskAnnotator::ScopedSetIpcHash scoped_set_ipc_hash(
-        heap_profiler_tag_);
+    // Annotate the posted task with |handler_tag_| as the IPC interface.
+    base::TaskAnnotator::ScopedSetIpcHash scoped_set_ipc_hash(handler_tag_);
     task_runner_->PostTask(FROM_HERE,
                            base::BindOnce(&SimpleWatcher::OnHandleReady,
                                           weak_factory_.GetWeakPtr(), watch_id_,
@@ -261,12 +263,16 @@ void SimpleWatcher::OnHandleReady(int watch_id,
 
   // NOTE: It's legal for |callback| to delete |this|.
   if (!callback.is_null()) {
-    TRACE_HEAP_PROFILER_API_SCOPED_TASK_EXECUTION event(heap_profiler_tag_);
+    TRACE_HEAP_PROFILER_API_SCOPED_TASK_EXECUTION event(handler_tag_);
     // Lot of janks caused are grouped to OnHandleReady tasks. This trace event
-    // helps identify the cause of janks. It is ok to pass |heap_profiler_tag_|
+    // helps identify the cause of janks. It is ok to pass |handler_tag_|
     // here since it is a string literal.
-    // TODO(927206): Consider renaming |heap_profiler_tag_|.
-    TRACE_EVENT0("toplevel", heap_profiler_tag_);
+    TRACE_EVENT("toplevel", "SimpleWatcher::OnHandleReady",
+                [this](perfetto::EventContext ctx) {
+                  ctx.event()
+                      ->set_chrome_mojo_event_info()
+                      ->set_watcher_notify_interface_tag(handler_tag_);
+                });
 
     base::WeakPtr<SimpleWatcher> weak_self = weak_factory_.GetWeakPtr();
     callback.Run(result, state);
diff --git a/chromium/mojo/public/cpp/system/simple_watcher.h b/chromium/mojo/public/cpp/system/simple_watcher.h
index 24123bcb905..3ccec253e88 100644
--- a/chromium/mojo/public/cpp/system/simple_watcher.h
+++ b/chromium/mojo/public/cpp/system/simple_watcher.h
@@ -90,7 +90,7 @@ class MOJO_CPP_SYSTEM_EXPORT SimpleWatcher {
                 ArmingPolicy arming_policy,
                 scoped_refptr<base::SequencedTaskRunner> runner =
                     base::SequencedTaskRunnerHandle::Get(),
-                const char* heap_profiler_tag = nullptr);
+                const char* handler_tag = nullptr);
   ~SimpleWatcher();
 
   // Indicates if the SimpleWatcher is currently watching a handle.
@@ -226,7 +226,7 @@ class MOJO_CPP_SYSTEM_EXPORT SimpleWatcher {
 
   // Tag used to ID memory allocations that originated from notifications in
   // this watcher.
-  const char* heap_profiler_tag_ = nullptr;
+  const char* handler_tag_ = nullptr;
 
   base::WeakPtrFactory<SimpleWatcher> weak_factory_{this};
 
diff --git a/chromium/mojo/public/cpp/test_support/lib/test_utils.cc b/chromium/mojo/public/cpp/test_support/lib/test_utils.cc
index 062106db864..6fa00a537ba 100644
--- a/chromium/mojo/public/cpp/test_support/lib/test_utils.cc
+++ b/chromium/mojo/public/cpp/test_support/lib/test_utils.cc
@@ -10,7 +10,7 @@
 #include <vector>
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/cpp/system/wait.h"
 #include "mojo/public/cpp/test_support/test_support.h"
diff --git a/chromium/mojo/public/interfaces/bindings/tests/BUILD.gn b/chromium/mojo/public/interfaces/bindings/tests/BUILD.gn
index 404d9cf94f4..6eda7da6d8a 100644
--- a/chromium/mojo/public/interfaces/bindings/tests/BUILD.gn
+++ b/chromium/mojo/public/interfaces/bindings/tests/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
 import("../../../tools/bindings/mojom.gni")
 
 group("test_data_deps") {
@@ -254,7 +255,8 @@ copy("validation_test_data") {
   outputs = [ "$root_gen_dir/layout_test_data/{{source_root_relative_dir}}/{{source_file_part}}" ]
 }
 
-action_foreach("validation_test_data_list") {
+# TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+python2_action_foreach("validation_test_data_list") {
   testonly = true
   script = "//mojo/public/tools/bindings/gen_data_files_list.py"
   inputs = mojom_generator_sources
diff --git a/chromium/mojo/public/js/BUILD.gn b/chromium/mojo/public/js/BUILD.gn
index 47ee8536397..e3febd86e77 100644
--- a/chromium/mojo/public/js/BUILD.gn
+++ b/chromium/mojo/public/js/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/closure_compiler/closure_args.gni")
 import("//third_party/closure_compiler/compile_js.gni")
@@ -9,7 +10,8 @@ import("//tools/grit/grit_rule.gni")
 
 interfaces_bindings_gen_dir = "$root_gen_dir/mojo/public/interfaces/bindings"
 
-action("bindings") {
+# TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+python2_action("bindings") {
   bindings_js_files = [
     # This must be the first file in the list, because it initializes global
     # variable |mojo| that the others need to refer to.
@@ -49,26 +51,71 @@ action("bindings") {
   deps = [ "//mojo/public/interfaces/bindings:bindings_js__generator" ]
 }
 
-bindings_lite_sources = [
-  "bindings_lite.js",
-  "interface_support.js",
-]
+template("concatenate_files") {
+  # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+  python2_action(target_name) {
+    script = "//mojo/public/tools/bindings/concatenate-files.py"
+    inputs = invoker.inputs
+    output = "$target_gen_dir/${invoker.output}"
+    outputs = [ output ]
+    args = rebase_path(inputs, root_build_dir) +
+           [ rebase_path(output, root_build_dir) ]
+    if (defined(invoker.deps)) {
+      deps = invoker.deps
+    }
+  }
+}
 
-bindings_lite_compiled_file = "$target_gen_dir/mojo_bindings_lite.js"
+concatenate_files("generate_mojo_internal_js") {
+  inputs = [
+    "mojo_internal_preamble.js.part",
+    "bindings_lite.js",
+  ]
+  output = "mojo_internal.js"
+}
+
+concatenate_files("generate_interface_support_js") {
+  inputs = [
+    "interface_support_preamble.js.part",
+    "interface_support.js",
+  ]
+  output = "interface_support.js"
+}
 
 js_library("bindings_lite_sources") {
-  sources = [ "compile_preamble.js" ] + bindings_lite_sources
+  sources = [
+    "$target_gen_dir/interface_support.js",
+    "$target_gen_dir/mojo_internal.js",
+    "compile_preamble.js",
+  ]
   deps = [ "//mojo/public/interfaces/bindings:bindings_js_library_for_compile" ]
+  extra_deps = [
+    ":generate_interface_support_js",
+    ":generate_mojo_internal_js",
+  ]
+}
+
+# All generated mojom JS modules consume the API defined by this module. The
+# uncompiled source is simply a concatenation of the various pieces listed
+# below.
+concatenate_files("bindings_uncompiled_module") {
+  inputs = [
+    "bindings_module_preamble.js.part",
+    "bindings_lite.js",
+    "$root_gen_dir/mojo/public/interfaces/bindings/interface_control_messages.mojom-lite.js",
+    "interface_support.js",
+    "bindings_uncompiled_module_export.js.part",
+  ]
+  output = "bindings_uncompiled.js"
+  deps = [ "//mojo/public/interfaces/bindings:bindings_js_library" ]
 }
 
 if (enable_mojom_closure_compile || enable_js_type_check) {
   js_binary("bindings_lite") {
-    outputs = [ bindings_lite_compiled_file ]
+    outputs = [ "$target_gen_dir/mojo_bindings_lite.js" ]
+    sources = []
     deps = [ ":bindings_lite_sources" ]
-    externs_list = [
-      "$externs_path/mojo_core.js",
-      "$externs_path/pending.js",
-    ]
+    externs_list = [ "$externs_path/mojo_core.js" ]
     closure_flags = strict_error_checking_closure_args + [
                       "compilation_level=ADVANCED_OPTIMIZATIONS",
                       "language_in=ECMASCRIPT_2017",
@@ -78,19 +125,61 @@ if (enable_mojom_closure_compile || enable_js_type_check) {
                       "isolation_mode=IIFE",
                     ]
   }
+
+  concatenate_files("bindings_compiled_module") {
+    inputs = [
+      "$target_gen_dir/mojo_bindings_lite.js",
+      "bindings_module_export.js.part",
+    ]
+    output = "bindings_compiled.js"
+    deps = [ ":bindings_lite" ]
+  }
+
+  copy("bindings_module") {
+    sources = [ "$target_gen_dir/bindings_compiled.js" ]
+    outputs = [ "$target_gen_dir/bindings.js" ]
+    deps = [ ":bindings_compiled_module" ]
+  }
 } else {
   action("bindings_lite") {
-    all_sources = bindings_lite_sources + [ "$root_gen_dir/mojo/public/interfaces/bindings/interface_control_messages.mojom-lite.js" ]
+    inputs = [
+      "$target_gen_dir/mojo_internal.js",
+      "$root_gen_dir/mojo/public/interfaces/bindings/interface_control_messages.mojom-lite-for-compile.js",
+      "$target_gen_dir/interface_support.js",
+    ]
     script = "//mojo/public/tools/bindings/concatenate_and_replace_closure_exports.py"
-    sources = all_sources
-    outputs = [ bindings_lite_compiled_file ]
-    args = rebase_path(all_sources, root_build_dir) +
-           [ rebase_path(bindings_lite_compiled_file, root_build_dir) ]
-    deps = [ "//mojo/public/interfaces/bindings:bindings_js__generator" ]
+    sources = inputs
+    outputs = [ "$target_gen_dir/mojo_bindings_lite.js" ]
+    args =
+        rebase_path(inputs, root_build_dir) +
+        [ rebase_path("$target_gen_dir/mojo_bindings_lite.js", root_build_dir) ]
+    deps = [
+      ":generate_interface_support_js",
+      ":generate_mojo_internal_js",
+      "//mojo/public/interfaces/bindings:bindings_js__generator",
+    ]
   }
+
+  copy("bindings_module") {
+    sources = [ "$target_gen_dir/bindings_uncompiled.js" ]
+    outputs = [ "$target_gen_dir/bindings.js" ]
+    deps = [ ":bindings_uncompiled_module" ]
+  }
+}
+
+# This is the library target used in the dependency tree of any JS libraries
+# or binaries compiling against mojom JS bindings. This library is functionally
+# equivalent to the bindings.js generated by the ":bindings_module" target and
+# used at runtime by all consumers, except that this module includes all type
+# annotations and is suitable for Closure compilation and type checking.
+js_library("bindings_uncompiled") {
+  sources = [ "$target_gen_dir/bindings_uncompiled.js" ]
+  extra_deps = [ ":bindings_uncompiled_module" ]
 }
 
 grit("resources") {
+  # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+  run_under_python2 = true
   source = "mojo_bindings_resources.grd"
 
   outputs = [
@@ -100,14 +189,10 @@ grit("resources") {
     "mojo_bindings_resources.pak",
   ]
 
-  grit_flags = [
-    "-E",
-    "root_gen_dir=" + rebase_path(root_gen_dir, root_build_dir),
-  ]
-
   deps = [
     ":bindings",
     ":bindings_lite",
+    ":bindings_module",
     "//mojo/public/mojom/base:base_js",
   ]
 }
diff --git a/chromium/mojo/public/js/bindings_lite.js b/chromium/mojo/public/js/bindings_lite.js
index d2521fc30b2..1821540fda8 100644
--- a/chromium/mojo/public/js/bindings_lite.js
+++ b/chromium/mojo/public/js/bindings_lite.js
@@ -1,33 +1,6 @@
 // Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-'use strict';
-
-goog.provide('mojo.internal');
-
-// "self" is always defined as opposed to "this", which isn't defined in
-// modules, or "window", which isn't defined in workers.
-/** @const {!Object} */
-mojo.internal.globalScope = self;
-
-/**
- * This is effectively the same as goog.provide, but it's made available under
- * the mojo.internal namespace to avoid potential collisions in certain
- * compilation environments.
- *
- * @param {string} namespace
- * @export
- */
-mojo.internal.exportModule = function(namespace) {
-  let current = mojo.internal.globalScope;
-  const parts = namespace.split('.');
-
-  for (let part; parts.length && (part = parts.shift());) {
-    if (!current[part])
-      current[part] = {};
-    current = current[part];
-  }
-};
 
 /** @const {number} */
 mojo.internal.kArrayHeaderSize = 8;
@@ -85,7 +58,7 @@ mojo.internal.align = function(size, alignment) {
 /**
  * @param {!DataView} dataView
  * @param {number} byteOffset
- * @param {number} value
+ * @param {number|bigint} value
  */
 mojo.internal.setInt64 = function(dataView, byteOffset, value) {
   if (mojo.internal.kHostLittleEndian) {
@@ -93,11 +66,12 @@ mojo.internal.setInt64 = function(dataView, byteOffset, value) {
         byteOffset, Number(BigInt(value) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
     dataView.setInt32(
-        byteOffset + 4, Number(BigInt(value) >> BigInt(32)),
+        byteOffset + 4,
+        Number((BigInt(value) >> BigInt(32)) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
   } else {
     dataView.setInt32(
-        byteOffset, Number(BigInt(value) >> BigInt(32)),
+        byteOffset, Number((BigInt(value) >> BigInt(32)) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
     dataView.setUint32(
         byteOffset + 4, Number(BigInt(value) & BigInt(0xffffffff)),
@@ -108,7 +82,7 @@ mojo.internal.setInt64 = function(dataView, byteOffset, value) {
 /**
  * @param {!DataView} dataView
  * @param {number} byteOffset
- * @param {number} value
+ * @param {number|bigint} value
  */
 mojo.internal.setUint64 = function(dataView, byteOffset, value) {
   if (mojo.internal.kHostLittleEndian) {
@@ -116,11 +90,12 @@ mojo.internal.setUint64 = function(dataView, byteOffset, value) {
         byteOffset, Number(BigInt(value) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
     dataView.setUint32(
-        byteOffset + 4, Number(BigInt(value) >> BigInt(32)),
+        byteOffset + 4,
+        Number((BigInt(value) >> BigInt(32)) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
   } else {
     dataView.setUint32(
-        byteOffset, Number(BigInt(value) >> BigInt(32)),
+        byteOffset, Number((BigInt(value) >> BigInt(32)) & BigInt(0xffffffff)),
         mojo.internal.kHostLittleEndian);
     dataView.setUint32(
         byteOffset + 4, Number(BigInt(value) & BigInt(0xffffffff)),
@@ -131,7 +106,7 @@ mojo.internal.setUint64 = function(dataView, byteOffset, value) {
 /**
  * @param {!DataView} dataView
  * @param {number} byteOffset
- * @return {number}
+ * @return {bigint}
  */
 mojo.internal.getInt64 = function(dataView, byteOffset) {
   let low, high;
@@ -142,12 +117,24 @@ mojo.internal.getInt64 = function(dataView, byteOffset) {
     low = dataView.getUint32(byteOffset + 4, mojo.internal.kHostLittleEndian);
     high = dataView.getInt32(byteOffset, mojo.internal.kHostLittleEndian);
   }
-  const value = (BigInt(high) << BigInt(32)) | BigInt(low);
-  if (value <= BigInt(Number.MAX_SAFE_INTEGER) &&
-      value >= BigInt(Number.MIN_SAFE_INTEGER)) {
-    return Number(value);
+  return (BigInt(high) << BigInt(32)) | BigInt(low);
+};
+
+/**
+ * @param {!DataView} dataView
+ * @param {number} byteOffset
+ * @return {bigint}
+ */
+mojo.internal.getUint64 = function(dataView, byteOffset) {
+  let low, high;
+  if (mojo.internal.kHostLittleEndian) {
+    low = dataView.getUint32(byteOffset, mojo.internal.kHostLittleEndian);
+    high = dataView.getUint32(byteOffset + 4, mojo.internal.kHostLittleEndian);
+  } else {
+    low = dataView.getUint32(byteOffset + 4, mojo.internal.kHostLittleEndian);
+    high = dataView.getUint32(byteOffset, mojo.internal.kHostLittleEndian);
   }
-  return value;
+  return (BigInt(high) << BigInt(32)) | BigInt(low);
 };
 
 /**
@@ -249,26 +236,6 @@ mojo.internal.computeTotalArraySize = function(arraySpec, value) {
   return totalSize;
 };
 
-/**
- * @param {!DataView} dataView
- * @param {number} byteOffset
- * @return {number}
- */
-mojo.internal.getUint64 = function(dataView, byteOffset) {
-  let low, high;
-  if (mojo.internal.kHostLittleEndian) {
-    low = dataView.getUint32(byteOffset, mojo.internal.kHostLittleEndian);
-    high = dataView.getUint32(byteOffset + 4, mojo.internal.kHostLittleEndian);
-  } else {
-    low = dataView.getUint32(byteOffset + 4, mojo.internal.kHostLittleEndian);
-    high = dataView.getUint32(byteOffset, mojo.internal.kHostLittleEndian);
-  }
-  const value = (BigInt(high) << BigInt(32)) | BigInt(low);
-  if (value <= BigInt(Number.MAX_SAFE_INTEGER))
-    return Number(value);
-  return value;
-};
-
 /** Owns an outgoing message buffer and facilitates serialization. */
 mojo.internal.Message = class {
   /**
@@ -683,7 +650,9 @@ mojo.internal.Decoder = class {
     const relativeOffset = this.decodeUint64(offset);
     if (relativeOffset == 0)
       return 0;
-    return this.data_.byteOffset + offset + relativeOffset;
+    if (relativeOffset > BigInt(Number.MAX_SAFE_INTEGER))
+      throw new Error('Mesage offset too large');
+    return this.data_.byteOffset + offset + Number(relativeOffset);
   }
 
   /**
diff --git a/chromium/mojo/public/js/bindings_module_export.js.part b/chromium/mojo/public/js/bindings_module_export.js.part
new file mode 100644
index 00000000000..455896d4ab1
--- /dev/null
+++ b/chromium/mojo/public/js/bindings_module_export.js.part
@@ -0,0 +1,3 @@
+const mojoTmp = self['mojo'];
+delete self['mojo'];
+export const mojo = mojoTmp;
diff --git a/chromium/mojo/public/js/bindings_module_preamble.js.part b/chromium/mojo/public/js/bindings_module_preamble.js.part
new file mode 100644
index 00000000000..1d00fd82e02
--- /dev/null
+++ b/chromium/mojo/public/js/bindings_module_preamble.js.part
@@ -0,0 +1,4 @@
+const mojo = {
+  internal: { interfaceSupport: {} },
+  interfaceControl: {}
+};
diff --git a/chromium/mojo/public/js/bindings_uncompiled_module_export.js.part b/chromium/mojo/public/js/bindings_uncompiled_module_export.js.part
new file mode 100644
index 00000000000..712a9e34ea4
--- /dev/null
+++ b/chromium/mojo/public/js/bindings_uncompiled_module_export.js.part
@@ -0,0 +1 @@
+export {mojo};
diff --git a/chromium/mojo/public/js/interface_support.js b/chromium/mojo/public/js/interface_support.js
index 6d95bb8ce7a..1810c790e0c 100644
--- a/chromium/mojo/public/js/interface_support.js
+++ b/chromium/mojo/public/js/interface_support.js
@@ -1,14 +1,6 @@
 // Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-'use strict';
-
-goog.require('mojo.interfaceControl.RUN_MESSAGE_ID');
-goog.require('mojo.interfaceControl.RunResponseMessageParamsSpec');
-goog.require('mojo.internal');
-
-goog.provide('mojo.internal.interfaceSupport');
-
 
 /**
  * Handles incoming interface control messages on a remote or router endpoint.
diff --git a/chromium/mojo/public/js/interface_support_preamble.js.part b/chromium/mojo/public/js/interface_support_preamble.js.part
new file mode 100644
index 00000000000..bb98866e4c5
--- /dev/null
+++ b/chromium/mojo/public/js/interface_support_preamble.js.part
@@ -0,0 +1,8 @@
+'use strict';
+
+goog.require('mojo.interfaceControl.RUN_MESSAGE_ID');
+goog.require('mojo.interfaceControl.RunResponseMessageParamsSpec');
+goog.require('mojo.internal');
+
+goog.provide('mojo.internal.interfaceSupport');
+
diff --git a/chromium/mojo/public/js/lib/interface_endpoint_client.js b/chromium/mojo/public/js/lib/interface_endpoint_client.js
index 9b45b69b05e..392cb59d297 100644
--- a/chromium/mojo/public/js/lib/interface_endpoint_client.js
+++ b/chromium/mojo/public/js/lib/interface_endpoint_client.js
@@ -33,12 +33,17 @@
   }
 
   InterfaceEndpointClient.prototype.initControllerIfNecessary_ = function() {
+    if (!this.handle_) {
+      return false;
+    }
+
     if (this.controller_ || this.handle_.pendingAssociation()) {
-      return;
+      return true;
     }
 
     this.controller_ = this.handle_.groupController().attachEndpointClient(
         this.handle_, this);
+    return true;
   };
 
   InterfaceEndpointClient.prototype.onAssociationEvent = function(
@@ -84,7 +89,9 @@
       return false;
     }
 
-    this.initControllerIfNecessary_();
+    if (!this.initControllerIfNecessary_()) {
+      return false;
+    }
     return this.controller_.sendMessage(message);
   };
 
@@ -99,7 +106,9 @@
       return Promise.reject();
     }
 
-    this.initControllerIfNecessary_();
+    if (!this.initControllerIfNecessary_()) {
+      return Promise.reject(Error('Endpoint has been closed'));
+    }
 
     // Reserve 0 in case we want it to convey special meaning in the future.
     var requestID = this.nextRequestID_++;
diff --git a/chromium/mojo/public/js/mojo_bindings_resources.grd b/chromium/mojo/public/js/mojo_bindings_resources.grd
index e86d260df3c..999a411ea9b 100644
--- a/chromium/mojo/public/js/mojo_bindings_resources.grd
+++ b/chromium/mojo/public/js/mojo_bindings_resources.grd
@@ -7,7 +7,7 @@
     <output filename="grit/mojo_bindings_resources_map.h"
         type="resource_map_header" />
     <output filename="grit/mojo_bindings_resources_map.cc"
-        type="resource_map_source" />
+        type="resource_file_map_source" />
     <output filename="mojo_bindings_resources.pak" type="data_package" />
   </outputs>
   <translations />
@@ -18,58 +18,89 @@
         <include name="IDR_MOJO_MOJO_BINDINGS_JS"
             file="${root_gen_dir}/mojo/public/js/mojo_bindings.js"
             use_base_dir="false"
+            resource_path="mojo/mojo/public/js/mojo_bindings.js"
             type="BINDATA" />
       </if>
+      <include name="IDR_MOJO_BINDINGS_JS"
+          file="${root_gen_dir}/mojo/public/js/bindings.js"
+          use_base_dir="false"
+          resource_path="mojo/mojo/public/js/bindings.js"
+          type="BINDATA" />
       <include name="IDR_MOJO_MOJO_BINDINGS_LITE_HTML"
           file="mojo_bindings_lite.html"
+          resource_path="mojo/mojo/public/js/mojo_bindings_lite.html"
           type="BINDATA" />
       <include name="IDR_MOJO_MOJO_BINDINGS_LITE_JS"
           file="${root_gen_dir}/mojo/public/js/mojo_bindings_lite.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/js/mojo_bindings_lite.js"
           type="BINDATA" />
       <include name="IDR_MOJO_BIG_BUFFER_MOJOM_HTML"
           file="${root_gen_dir}/mojo/public/mojom/base/big_buffer.mojom.html"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/big_buffer.mojom.html"
           type="BINDATA" />
       <include name="IDR_MOJO_BIG_BUFFER_MOJOM_LITE_JS"
           file="${root_gen_dir}/mojo/public/mojom/base/big_buffer.mojom-lite.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/big_buffer.mojom-lite.js"
           type="BINDATA" />
-      <include name="IDR_MOJO_FILE_MOJOM_HTML"
-          file="${root_gen_dir}/mojo/public/mojom/base/file.mojom.html"
+      <include name="IDR_MOJO_BIG_BUFFER_MOJOM_WEBUI_JS"
+          file="${root_gen_dir}/mojom-webui/mojo/public/mojom/base/big_buffer.mojom-webui.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/big_buffer.mojom-webui.js"
           type="BINDATA" />
-      <include name="IDR_MOJO_FILE_MOJOM_LITE_JS"
-          file="${root_gen_dir}/mojo/public/mojom/base/file.mojom-lite.js"
+      <include name="IDR_MOJO_FILE_MOJOM_WEBUI_JS"
+          file="${root_gen_dir}/mojom-webui/mojo/public/mojom/base/file.mojom-webui.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/file.mojom-webui.js"
           type="BINDATA" />
       <include name="IDR_MOJO_STRING16_MOJOM_HTML"
           file="${root_gen_dir}/mojo/public/mojom/base/string16.mojom.html"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/string16.mojom.html"
           type="BINDATA" />
       <include name="IDR_MOJO_STRING16_MOJOM_LITE_JS"
           file="${root_gen_dir}/mojo/public/mojom/base/string16.mojom-lite.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/string16.mojom-lite.js"
+          type="BINDATA" />
+      <include name="IDR_MOJO_STRING16_MOJOM_WEBUI_JS"
+          file="${root_gen_dir}/mojom-webui/mojo/public/mojom/base/string16.mojom-webui.js"
+          use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/string16.mojom-webui.js"
           type="BINDATA" />
       <include name="IDR_MOJO_TEXT_DIRECTION_MOJOM_HTML"
           file="${root_gen_dir}/mojo/public/mojom/base/text_direction.mojom.html"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/text_direction.mojom.html"
           type="BINDATA" />
       <include name="IDR_MOJO_TEXT_DIRECTION_MOJOM_LITE_JS"
           file="${root_gen_dir}/mojo/public/mojom/base/text_direction.mojom-lite.js"
           use_base_dir="false"
+          resource_path="mojo/mojo/public/mojom/base/text_direction.mojom-lite.js"
           type="BINDATA" />
       <if expr="is_win or is_macosx or is_linux or is_android">
+        <include name="IDR_MOJO_PROCESS_ID_MOJOM_WEBUI_JS"
+            file="${root_gen_dir}/mojom-webui/mojo/public/mojom/base/process_id.mojom-webui.js"
+            use_base_dir="false"
+            resource_path="mojo/mojo/public/mojom/base/process_id.mojom-webui.js"
+            type="BINDATA" />
         <include name="IDR_MOJO_TIME_MOJOM_HTML"
             file="${root_gen_dir}/mojo/public/mojom/base/time.mojom.html"
             use_base_dir="false"
-            type="BINDATA"
-            compress="gzip" />
+            resource_path="mojo/mojo/public/mojom/base/time.mojom.html"
+          type="BINDATA" />
         <include name="IDR_MOJO_TIME_MOJOM_LITE_JS"
             file="${root_gen_dir}/mojo/public/mojom/base/time.mojom-lite.js"
+            resource_path="mojo/mojo/public/mojom/base/time.mojom-lite.js"
             use_base_dir="false"
-            type="BINDATA"
-            compress="gzip" />
+            type="BINDATA" />
+        <include name="IDR_MOJO_TIME_MOJOM_WEBUI_JS"
+            file="${root_gen_dir}/mojom-webui/mojo/public/mojom/base/time.mojom-webui.js"
+            use_base_dir="false"
+            resource_path="mojo/mojo/public/mojom/base/time.mojom-webui.js"
+            type="BINDATA" />
       </if>
     </includes>
   </release>
diff --git a/chromium/mojo/public/js/mojo_internal_preamble.js.part b/chromium/mojo/public/js/mojo_internal_preamble.js.part
new file mode 100644
index 00000000000..28a18b25150
--- /dev/null
+++ b/chromium/mojo/public/js/mojo_internal_preamble.js.part
@@ -0,0 +1,27 @@
+'use strict';
+
+goog.provide('mojo.internal');
+
+// "self" is always defined as opposed to "this", which isn't defined in
+// modules, or "window", which isn't defined in workers.
+/** @const {!Object} */
+mojo.internal.globalScope = self;
+
+/**
+ * This is effectively the same as goog.provide, but it's made available under
+ * the mojo.internal namespace to avoid potential collisions in certain
+ * compilation environments.
+ *
+ * @param {string} namespace
+ * @export
+ */
+mojo.internal.exportModule = function(namespace) {
+  let current = mojo.internal.globalScope;
+  const parts = namespace.split('.');
+
+  for (let part; parts.length && (part = parts.shift());) {
+    if (!current[part])
+      current[part] = {};
+    current = current[part];
+  }
+};
diff --git a/chromium/mojo/public/mojom/base/BUILD.gn b/chromium/mojo/public/mojom/base/BUILD.gn
index 61bb72a6183..53acc61d85d 100644
--- a/chromium/mojo/public/mojom/base/BUILD.gn
+++ b/chromium/mojo/public/mojom/base/BUILD.gn
@@ -21,6 +21,7 @@ mojom_component("base") {
     "message_pump_type.mojom",
     "process_id.mojom",
     "read_only_buffer.mojom",
+    "read_only_file.mojom",
     "ref_counted_memory.mojom",
     "shared_memory.mojom",
     "string16.mojom",
@@ -42,6 +43,8 @@ mojom_component("base") {
     enabled_features += [ "file_path_is_string" ]
   }
 
+  webui_module_path = "chrome://resources/mojo/mojo/public/mojom/base"
+
   output_prefix = "mojo_base_mojom"
   macro_prefix = "MOJO_BASE_MOJOM"
 
@@ -121,6 +124,24 @@ mojom_component("base") {
     {
       types = [
         {
+          mojom = "mojo_base.mojom.ReadOnlyFile"
+          cpp = "::base::File"
+          move_only = true
+          nullable_is_same_type = true
+          force_serialize = true
+        },
+      ]
+      traits_headers =
+          [ "//mojo/public/cpp/base/read_only_file_mojom_traits.h" ]
+      traits_public_deps = [
+        "//base",
+        "//mojo/public/cpp/base",
+        "//mojo/public/cpp/base:shared_typemap_traits",
+      ]
+    },
+    {
+      types = [
+        {
           mojom = "mojo_base.mojom.GenericPendingReceiver"
           cpp = "::mojo::GenericPendingReceiver"
           move_only = true
diff --git a/chromium/mojo/public/mojom/base/big_string.mojom b/chromium/mojo/public/mojom/base/big_string.mojom
index c971caf5674..fd0a5c00690 100644
--- a/chromium/mojo/public/mojom/base/big_string.mojom
+++ b/chromium/mojo/public/mojom/base/big_string.mojom
@@ -14,6 +14,7 @@ import "mojo/public/mojom/base/big_buffer.mojom";
 // an arbitrarily large amount of data (available memory permitting) without
 // negatively impacting IPC performance or hitting hard message size
 // boundaries.
+[Stable]
 struct BigString {
   mojo_base.mojom.BigBuffer data;
 };
diff --git a/chromium/mojo/public/mojom/base/file.mojom b/chromium/mojo/public/mojom/base/file.mojom
index 199af80a262..6c7f5043be0 100644
--- a/chromium/mojo/public/mojom/base/file.mojom
+++ b/chromium/mojo/public/mojom/base/file.mojom
@@ -5,6 +5,7 @@
 module mojo_base.mojom;
 
 // Corresponds to |base::File| in base/files/file.h
+[Stable]
 struct File {
   handle<platform> fd;
   bool async;
diff --git a/chromium/mojo/public/mojom/base/process_id.mojom b/chromium/mojo/public/mojom/base/process_id.mojom
index f3b17780a51..3a6e09f4242 100644
--- a/chromium/mojo/public/mojom/base/process_id.mojom
+++ b/chromium/mojo/public/mojom/base/process_id.mojom
@@ -4,6 +4,7 @@
 
 module mojo_base.mojom;
 
+[Stable]
 struct ProcessId {
   // This is the storage for the pid, on windows the pid is a DWORD and the
   // value can be DWORD_MAX which maps gracefully to uint32 while on linux
diff --git a/chromium/mojo/public/mojom/base/read_only_file.mojom b/chromium/mojo/public/mojom/base/read_only_file.mojom
new file mode 100644
index 00000000000..6f361ffe7f2
--- /dev/null
+++ b/chromium/mojo/public/mojom/base/read_only_file.mojom
@@ -0,0 +1,20 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module mojo_base.mojom;
+
+// Corresponds to |base::File| in base/files/file.h but, on most
+// platforms, will not serialise handles which are writable. At
+// present this only supports physically backed files, but this may be
+// relaxed in future.
+//
+// SECURITY_NOTE: This type is an indication that a readonly handle can
+// be provided. A sandboxed process should ensure that the handle cannot
+// be made writable. This may not be possible on all platforms.
+//
+// See |file_mojom_traits.cc| for details.
+struct ReadOnlyFile {
+  handle<platform> fd;
+  bool async;
+};
diff --git a/chromium/mojo/public/mojom/base/time.mojom b/chromium/mojo/public/mojom/base/time.mojom
index 64777e56754..5eb3fa5cee2 100644
--- a/chromium/mojo/public/mojom/base/time.mojom
+++ b/chromium/mojo/public/mojom/base/time.mojom
@@ -11,10 +11,12 @@ struct Time {
   int64 internal_value;
 };
 
+[Stable]
 struct TimeDelta {
   int64 microseconds;
 };
 
+[Stable]
 struct TimeTicks {
   // The internal value is expressed in terms of microseconds since a fixed but
   // intentionally unspecified epoch.
diff --git a/chromium/mojo/public/mojom/base/token.mojom b/chromium/mojo/public/mojom/base/token.mojom
index ac5f32c37b9..62f85b3f0c9 100644
--- a/chromium/mojo/public/mojom/base/token.mojom
+++ b/chromium/mojo/public/mojom/base/token.mojom
@@ -5,6 +5,7 @@
 module mojo_base.mojom;
 
 // Corresponds to |base::Token| defined in base/token.h
+[Stable]
 struct Token {
   uint64 high;
   uint64 low;
diff --git a/chromium/mojo/public/mojom/base/values.mojom b/chromium/mojo/public/mojom/base/values.mojom
index ea7c1fa590f..5ffe845af53 100644
--- a/chromium/mojo/public/mojom/base/values.mojom
+++ b/chromium/mojo/public/mojom/base/values.mojom
@@ -8,6 +8,7 @@ module mojo_base.mojom;
 //
 // One notable caveat is that Value supports arbitrary binary data, which JSON
 // does not support natively.
+[Stable]
 union Value {
   // Null type placeholder. This field is never used.
   uint8 null_value;
@@ -29,10 +30,12 @@ union Value {
 // declaration. Though both of these types are mapped to base::Value in C++,
 // the generated deserialization will guarantee that the method is only invoked
 // with a base::Value of the correct subtype.
+[Stable]
 struct DictionaryValue {
   map<string, Value> storage;
 };
 
+[Stable]
 struct ListValue {
   array<Value> storage;
 };
diff --git a/chromium/mojo/public/tools/bindings/BUILD.gn b/chromium/mojo/public/tools/bindings/BUILD.gn
index 8ba6e922a4b..f25c4afa8b0 100644
--- a/chromium/mojo/public/tools/bindings/BUILD.gn
+++ b/chromium/mojo/public/tools/bindings/BUILD.gn
@@ -2,10 +2,12 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/jinja2/jinja2.gni")
 
-action("precompile_templates") {
+# TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+python2_action("precompile_templates") {
   sources = mojom_generator_sources
   sources += [
     "$mojom_generator_root/generators/cpp_templates/enum_macros.tmpl",
@@ -69,11 +71,16 @@ action("precompile_templates") {
     "$mojom_generator_root/generators/js_templates/fuzzing.tmpl",
     "$mojom_generator_root/generators/js_templates/interface_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/enum_definition.tmpl",
+    "$mojom_generator_root/generators/js_templates/lite/enum_definition_for_module.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/interface_definition.tmpl",
+    "$mojom_generator_root/generators/js_templates/lite/interface_definition_for_module.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/module_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/mojom-lite.js.tmpl",
+    "$mojom_generator_root/generators/js_templates/lite/mojom.m.js.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/struct_definition.tmpl",
+    "$mojom_generator_root/generators/js_templates/lite/struct_definition_for_module.tmpl",
     "$mojom_generator_root/generators/js_templates/lite/union_definition.tmpl",
+    "$mojom_generator_root/generators/js_templates/lite/union_definition_for_module.tmpl",
     "$mojom_generator_root/generators/js_templates/module.amd.tmpl",
     "$mojom_generator_root/generators/js_templates/module_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/struct_definition.tmpl",
diff --git a/chromium/mojo/public/tools/bindings/README.md b/chromium/mojo/public/tools/bindings/README.md
index 228a2d3355b..7ddbb79a6ff 100644
--- a/chromium/mojo/public/tools/bindings/README.md
+++ b/chromium/mojo/public/tools/bindings/README.md
@@ -418,6 +418,13 @@ interesting attributes supported today.
     strict presubmit check. See [Versioning](#Versioning) for more details on
     backward-compatibility constraints.
 
+**`[Uuid=<UUID>]`**
+:  Specifies a UUID to be associated with a given interface. The UUID is
+   intended to remain stable across all changes to the interface definition,
+   including name changes. The value given for this attribute should be a
+   standard UUID string representation as specified by RFC 4122. New UUIDs can
+   be generated with common tools such as `uuidgen`.
+
 **`[EnableIf=value]`**
 :   The `EnableIf` attribute is used to conditionally enable definitions when
     the mojom is parsed. If the `mojom` target in the GN file does not include
@@ -712,6 +719,24 @@ values and will need to deal with them gracefully. See
 [C++ Versioning Considerations](/mojo/public/cpp/bindings/README.md#Versioning-Considerations)
 for details.
 
+### Renaming versioned structs
+It's possible to rename versioned structs by using the `[RenamedFrom]` attribute.
+RenamedFrom
+
+``` cpp
+module asdf.mojom;
+
+// Old version:
+[Stable]
+struct OldStruct {
+};
+
+// New version:
+[Stable, RenamedFrom="asdf.mojom.OldStruct"]
+struct NewStruct {
+};
+```
+
 ## Grammar Reference
 
 Below is the (BNF-ish) context-free grammar of the Mojom language:
diff --git a/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_declaration.tmpl b/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_declaration.tmpl
index f8b28e79c3b..a1a87fb125d 100644
--- a/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_declaration.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_declaration.tmpl
@@ -16,6 +16,10 @@ class {{export_attribute}} {{interface.name}}
     : public {{interface.name}}InterfaceBase {
  public:
   static const char Name_[];
+{%-  if interface.uuid %}
+  static constexpr base::Token Uuid_{ {{interface.uuid[0]}}ULL,
+                                      {{interface.uuid[1]}}ULL };
+{%-  endif %}
   static constexpr uint32_t Version_ = {{interface.version}};
   static constexpr bool PassesAssociatedKinds_ = {% if interface|passes_associated_kinds %}true{% else %}false{% endif %};
   static constexpr bool HasSyncMethods_ = {% if interface|has_sync_methods %}true{% else %}false{% endif %};
diff --git a/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl b/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl
index d8d10b3c672..c3ca8506c11 100644
--- a/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl
@@ -32,6 +32,9 @@ std::move(p_{{param.name}})
 
 {#--- Begin #}
 const char {{class_name}}::Name_[] = "{{module_namespace}}.{{class_name}}";
+{%-  if interface.uuid %}
+constexpr base::Token {{class_name}}::Uuid_;
+{%-  endif %}
 
 {#--- Constants #}
 {%-  for constant in interface.constants %}
diff --git a/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl b/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
index eb7fd89a4e7..e934b41c728 100644
--- a/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
@@ -59,6 +59,9 @@ class {{export_attribute}} {{struct.name}} {
   template <typename T, {{struct.name}}::EnableIfSame<T>* = nullptr>
   bool Equals(const T& other) const;
 
+  template <typename T, {{struct.name}}::EnableIfSame<T>* = nullptr>
+  bool operator==(const T& rhs) const { return Equals(rhs); }
+
 {%- if struct|is_hashable %}
   size_t Hash(size_t seed) const;
 {%- endif %}
diff --git a/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_union_class_declaration.tmpl b/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_union_class_declaration.tmpl
index 40603a7fe53..05686c9ddf7 100644
--- a/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_union_class_declaration.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/cpp_templates/wrapper_union_class_declaration.tmpl
@@ -49,6 +49,11 @@ class {{export_attribute}} {{union.name}} {
                 T, {{union.name}}>::value>::type* = nullptr>
   bool Equals(const T& other) const;
 
+  template <typename T,
+            typename std::enable_if<std::is_same<
+                T, {{union.name}}>::value>::type* = nullptr>
+  bool operator==(const T& rhs) const { return Equals(rhs); }
+
 {%- if union|is_hashable %}
   size_t Hash(size_t seed) const;
 {%- endif %}
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/enum_definition_for_module.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/enum_definition_for_module.tmpl
new file mode 100644
index 00000000000..27c4817c9d9
--- /dev/null
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/enum_definition_for_module.tmpl
@@ -0,0 +1,23 @@
+{%- macro enum_def(enum) -%}
+/**
+ * @const { {$: !mojo.internal.MojomType} }
+ */
+export const {{enum|type_in_js_module}}Spec = { $: mojo.internal.Enum() };
+
+/**
+ * @enum {number}
+ */
+export const {{enum|type_in_js_module}} = {
+  {# Set up the enum here, but fill out the values later. #}
+{%-   for field in enum.fields %}
+  {{field.name}}: {{field.numeric_value}},
+{%-   endfor %}
+{%-   if enum.min_value is not none %}
+  MIN_VALUE: {{enum.min_value}},
+{%-   endif %}
+{%-   if enum.max_value is not none %}
+  MAX_VALUE: {{enum.max_value}},
+{%-   endif %}
+};
+
+{%- endmacro %}
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/interface_definition_for_module.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/interface_definition_for_module.tmpl
new file mode 100644
index 00000000000..bc000ba3d82
--- /dev/null
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/interface_definition_for_module.tmpl
@@ -0,0 +1,211 @@
+{% macro generateMethodAnnotation(method) %}
+  /**
+{%-   for param in method.parameters %}
+   * @param { {{param.kind|param_type_in_js_module}} } {{param.name|sanitize_identifier}}
+{%-   endfor -%}
+{%-   if method.response_parameters != None %}
+{%-     if method.response_parameters|length == 0 %}
+   * @return {!Promise}
+{%-     else %}
+   * @return {!Promise<{
+{%-       for response_parameter in method.response_parameters %}
+        {{response_parameter.name}}: {{response_parameter.kind|param_type_in_js_module}},
+{%-       endfor %}
+   *  }>}
+{%-     endif %}
+{%-   endif %}
+   */
+{% endmacro %}
+
+/**
+ * @implements {mojo.internal.interfaceSupport.PendingReceiver}
+ */
+export const {{interface.name}}PendingReceiver = class {
+  /** @param {!MojoHandle} handle */
+  constructor(handle) {
+    /** @public {!MojoHandle} */
+    this.handle = handle;
+  }
+};
+
+/** @interface */
+export const {{interface.name}}Interface = class {
+{%-  for method in interface.methods %}
+  {{generateMethodAnnotation(method)}}
+  {{method.name}}(
+{%-   for param in method.parameters -%}
+{{param.name|sanitize_identifier}}{% if not loop.last %}, {% endif %}
+{%-   endfor -%}
+) {}
+{%- endfor %}
+};
+
+/**
+ * @implements { {{interface.name}}Interface }
+ */
+export const {{interface.name}}Remote = class {
+  /** @param {MojoHandle=} opt_handle */
+  constructor(opt_handle) {
+    /**
+     * @private {!mojo.internal.interfaceSupport.InterfaceRemoteBase<!{{interface.name}}PendingReceiver>}
+     */
+    this.proxy =
+        new mojo.internal.interfaceSupport.InterfaceRemoteBase(
+          {{interface.name}}PendingReceiver,
+          opt_handle);
+
+    /**
+     * @public {!mojo.internal.interfaceSupport.InterfaceRemoteBaseWrapper<!{{interface.name}}PendingReceiver>}
+     */
+    this.$ = new mojo.internal.interfaceSupport.InterfaceRemoteBaseWrapper(this.proxy);
+
+    /** @public {!mojo.internal.interfaceSupport.ConnectionErrorEventRouter} */
+    this.onConnectionError = this.proxy.getConnectionErrorEventRouter();
+  }
+
+{%- for method in interface.methods -%}
+{%-   set interface_message_id =
+          interface.mojom_name ~ "_" ~ method.mojom_name %}
+
+  {{generateMethodAnnotation(method)}}
+  {{method.name}}(
+{%- for param in method.parameters %}
+      {{param.name}}{%- if not loop.last %},{% endif %}
+{%- endfor -%}) {
+{%- if method.response_parameters != None %}
+    return this.proxy.sendMessage(
+{%- else %}
+    this.proxy.sendMessage(
+{%- endif %}
+        {{method.ordinal}},
+        {{interface_message_id}}_ParamsSpec.$,
+{%-   if method.response_parameters != None %}
+        {{interface_message_id}}_ResponseParamsSpec.$,
+{%-   else %}
+        null,
+{%-   endif %}
+        [
+{%- for param in method.parameters %}
+          {{param.name}}{%- if not loop.last %},{% endif %}
+{%- endfor %}
+        ]);
+  }
+{%-  endfor %}
+};
+
+/**
+ * An object which receives request messages for the {{interface.name}}
+ * mojom interface. Must be constructed over an object which implements that
+ * interface.
+ */
+export const {{interface.name}}Receiver = class {
+  /**
+   * @param {!{{interface.name}}Interface } impl
+   */
+  constructor(impl) {
+    /** @private {!mojo.internal.interfaceSupport.InterfaceReceiverHelperInternal<!{{interface.name}}Remote>} */
+    this.helper_internal_ = new mojo.internal.interfaceSupport.InterfaceReceiverHelperInternal(
+        {{interface.name}}Remote);
+
+    /**
+     * @public {!mojo.internal.interfaceSupport.InterfaceReceiverHelper<!{{interface.name}}Remote>}
+     */
+    this.$ = new mojo.internal.interfaceSupport.InterfaceReceiverHelper(this.helper_internal_);
+
+{%  for method in interface.methods %}
+{%-   set interface_message_id =
+          interface.mojom_name ~ "_" ~ method.mojom_name %}
+    this.helper_internal_.registerHandler(
+        {{method.ordinal}},
+        {{interface_message_id}}_ParamsSpec.$,
+{%-   if method.response_parameters != None %}
+        {{interface_message_id}}_ResponseParamsSpec.$,
+{%-   else %}
+        null,
+{%-   endif %}
+        impl.{{method.name}}.bind(impl));
+{%- endfor %}
+    /** @public {!mojo.internal.interfaceSupport.ConnectionErrorEventRouter} */
+    this.onConnectionError = this.helper_internal_.getConnectionErrorEventRouter();
+  }
+};
+
+export const {{interface.name}} = class {
+  /**
+   * @return {!string}
+   */
+  static get $interfaceName() {
+    return "{{mojom_namespace}}.{{interface.name}}";
+  }
+
+  /**
+   * Returns a remote for this interface which sends messages to the browser.
+   * The browser must have an interface request binder registered for this
+   * interface and accessible to the calling document's frame.
+   *
+   * @return {!{{interface.name}}Remote}
+   */
+  static getRemote() {
+    let remote = new {{interface.name}}Remote;
+    Mojo.bindInterface("{{mojom_namespace}}.{{interface.name}}",
+                       remote.$.bindNewPipeAndPassReceiver().handle);
+    return remote;
+  }
+};
+
+{#--- Enums #}
+{% from "lite/enum_definition_for_module.tmpl" import enum_def with context %}
+{%- for enum in interface.enums %}
+{{enum_def(enum)}}
+{%-  endfor %}
+
+/**
+ * An object which receives request messages for the {{interface.name}}
+ * mojom interface and dispatches them as callbacks. One callback receiver exists
+ * on this object for each message defined in the mojom interface, and each
+ * receiver can have any number of listeners added to it.
+ */
+export const {{interface.name}}CallbackRouter = class {
+  constructor() {
+    this.helper_internal_ = new mojo.internal.interfaceSupport.InterfaceReceiverHelperInternal(
+      {{interface.name}}Remote);
+
+    /**
+     * @public {!mojo.internal.interfaceSupport.InterfaceReceiverHelper<!{{interface.name}}Remote>}
+     */
+    this.$ = new mojo.internal.interfaceSupport.InterfaceReceiverHelper(this.helper_internal_);
+
+    this.router_ = new mojo.internal.interfaceSupport.CallbackRouter;
+{%  for method in interface.methods %}
+{%-   set interface_message_id =
+          interface.mojom_name ~ "_" ~ method.mojom_name %}
+    /**
+     * @public {!mojo.internal.interfaceSupport.InterfaceCallbackReceiver}
+     */
+    this.{{method.name}} =
+        new mojo.internal.interfaceSupport.InterfaceCallbackReceiver(
+            this.router_);
+
+    this.helper_internal_.registerHandler(
+        {{method.ordinal}},
+        {{interface_message_id}}_ParamsSpec.$,
+{%-   if method.response_parameters != None %}
+        {{interface_message_id}}_ResponseParamsSpec.$,
+        this.{{method.name}}.createReceiverHandler(true /* expectsResponse */));
+{%-   else %}
+        null,
+        this.{{method.name}}.createReceiverHandler(false /* expectsResponse */));
+{%-   endif %}
+{%- endfor %}
+    /** @public {!mojo.internal.interfaceSupport.ConnectionErrorEventRouter} */
+    this.onConnectionError = this.helper_internal_.getConnectionErrorEventRouter();
+  }
+
+  /**
+   * @param {number} id An ID returned by a prior call to addListener.
+   * @return {boolean} True iff the identified listener was found and removed.
+   */
+  removeListener(id) {
+    return this.router_.removeListener(id);
+  }
+};
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/module_definition.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/module_definition.tmpl
index e8124d4a865..99422f42f30 100644
--- a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/module_definition.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/module_definition.tmpl
@@ -8,8 +8,7 @@ goog.provide('{{module.namespace}}.{{constant.name}}');
  * @const { {{constant.kind|lite_closure_type_with_nullability}} }
  * @export
  */
-{{module.namespace}}.{{constant.name}} =
-    {{constant.value|expression_to_text_lite}};
+{{module.namespace}}.{{constant.name}} = {{constant|constant_value}};
 {%- endfor %}
 
 {#--- Enums #}
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom-lite.js.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom-lite.js.tmpl
index a02c7a32077..e057457d615 100644
--- a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom-lite.js.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom-lite.js.tmpl
@@ -1,7 +1,11 @@
+{# For bindings internals, generated code is concatenated into a larger module
+ # at build time, so we avoid a superfluous file header here. #}
+{%- if not for_bindings_internals -%}
 // Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 'use strict';
+{%- endif %}
 
 {% if generate_closure_exports -%}
 goog.require('mojo.internal');
@@ -11,7 +15,7 @@ goog.require('mojo.internal.interfaceSupport');
 {% for kind in module.imported_kinds.values() %}
 goog.require('{{kind|lite_js_import_name}}');
 {%- endfor %}
-{% else %}
+{% elif not for_bindings_internals  %}
 mojo.internal.exportModule('{{module.namespace}}');
 {% endif %}
 
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom.m.js.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom.m.js.tmpl
new file mode 100644
index 00000000000..659d6480c9e
--- /dev/null
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/mojom.m.js.tmpl
@@ -0,0 +1,66 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+{% if not for_bindings_internals -%}
+import {mojo} from '{{bindings_library_path}}';
+{%- endif %}
+
+{% for path, kinds in js_module_imports.items() -%}
+import {
+{%- for kind in kinds %}
+{%-   for item in kind|imports_for_kind %}
+  {{item.name}} as {{item.alias}}
+{%-     if not loop.last -%},{% endif -%}
+{%-   endfor %}
+{%- if not loop.last -%},{% endif -%}
+{%- endfor %}
+} from '{{path}}';
+
+{% endfor -%}
+
+{#--- Constants #}
+{%- for constant in module.constants %}
+/**
+ * @const { {{constant.kind|type_in_js_module_with_nullability}} }
+ */
+export const {{constant.name}} = {{constant|constant_value_in_js_module}};
+
+{% endfor -%}
+
+{#--- Enums #}
+{%- from "lite/enum_definition_for_module.tmpl" import enum_def with context %}
+{%- for enum in enums %}
+{{enum_def(enum)}}
+{%  endfor -%}
+
+{#--- Interfaces #}
+{%- for interface in interfaces %}
+{%   include "lite/interface_definition_for_module.tmpl" %}
+{%- endfor %}
+
+{#--- Struct and Union forward declarations #}
+{%  for struct in structs %}
+/**
+ * @const { {$:!mojo.internal.MojomType}}
+ */
+export const {{struct.name}}Spec =
+    { $: /** @type {!mojo.internal.MojomType} */ ({}) };
+{% endfor %}
+{%- for union in unions %}
+/**
+ * @const { {$:!mojo.internal.MojomType} }
+ */
+export const {{union.name}}Spec =
+    { $: /** @type {!mojo.internal.MojomType} */ ({}) };
+{% endfor %}
+
+{#--- Struct definitions #}
+{%  for struct in structs %}
+{%-   include "lite/struct_definition_for_module.tmpl" %}
+{% endfor -%}
+
+{#--- Union definitions #}
+{%  for union in unions %}
+{%-   include "lite/union_definition_for_module.tmpl" %}
+{% endfor %}
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition.tmpl
index 1d6acbcb5d7..2e4eb953412 100644
--- a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition.tmpl
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition.tmpl
@@ -4,7 +4,7 @@
  * @export
  */
 {{module.namespace}}.{{struct.name}}_{{constant.name}} =
-    {{constant.value|expression_to_text_lite}};
+    {{constant|constant_value}};
 {%  endfor %}
 
 {%- from "lite/enum_definition.tmpl" import enum_def with context %}
@@ -40,6 +40,7 @@ mojo.internal.Struct(
 
 {%  if generate_closure_exports -%}
 goog.provide('{{module.namespace}}.{{struct.name}}');
+{%- endif %}
 
 /** @record */
 {{module.namespace}}.{{struct.name}} = class {
@@ -51,4 +52,3 @@ goog.provide('{{module.namespace}}.{{struct.name}}');
   }
 };
 
-{%- endif %}
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition_for_module.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition_for_module.tmpl
new file mode 100644
index 00000000000..b6ef3829b6f
--- /dev/null
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/struct_definition_for_module.tmpl
@@ -0,0 +1,49 @@
+{%  for constant in struct.constants %}
+/**
+ * @const { {{constant.kind|type_in_js_module_with_nullability}} }
+ */
+export const {{struct.name}}_{{constant.name}} =
+    {{constant|constant_value_in_js_module}};
+{%  endfor %}
+
+{%- from "lite/enum_definition_for_module.tmpl" import enum_def with context %}
+{%  for enum in struct.enums %}
+{{enum_def(enum)}}
+{%  endfor %}
+
+mojo.internal.Struct(
+    {{struct.name}}Spec.$,
+    '{{struct.name}}',
+    {{struct.packed|payload_size}},
+    [
+{%- for packed_field in struct.packed.packed_fields_in_ordinal_order %}
+      mojo.internal.StructField(
+        '{{packed_field.field.name}}', {{packed_field.offset}},
+        {% if packed_field.field.kind|is_bool_kind %}{{packed_field.bit}}
+        {%- else %}0{% endif %},
+        {{packed_field.field.kind|spec_type_in_js_module}},
+        {{packed_field.field|default_value_in_js_module}},
+{%-   if packed_field.field.kind.is_nullable %}
+        true /* nullable */),
+{%-   else %}
+        false /* nullable */),
+{%-   endif %}
+{%- endfor %}
+    ]);
+
+{% if generate_struct_deserializers %}
+export const {{struct.name}}_Deserialize =
+    mojo.internal.createStructDeserializer({{struct.name}}Spec.$);
+{% endif %}
+
+/**
+ * @record
+ */
+export const {{struct.name}} = class {
+  constructor() {
+{%- for packed_field in struct.packed.packed_fields %}
+    /** @type { {{packed_field.field.kind|field_type_in_js_module}} } */
+    this.{{packed_field.field.name}};
+{%-  endfor %}
+  }
+};
diff --git a/chromium/mojo/public/tools/bindings/generators/js_templates/lite/union_definition_for_module.tmpl b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/union_definition_for_module.tmpl
new file mode 100644
index 00000000000..68be8b22b56
--- /dev/null
+++ b/chromium/mojo/public/tools/bindings/generators/js_templates/lite/union_definition_for_module.tmpl
@@ -0,0 +1,22 @@
+mojo.internal.Union(
+    {{union.name}}Spec.$, '{{union.name}}',
+    {
+{%- for field in union.fields %}
+      '{{field.name}}': {
+        'ordinal': {{field.ordinal}},
+        'type': {{field.kind|spec_type_in_js_module}},
+{%-    if field.kind.is_nullable %}
+        'nullable': true,
+{%-    endif %}
+      },
+{%- endfor %}
+    });
+
+/**
+ * @typedef { {
+{%- for field in union.fields %}
+ *   {{field.name}}: ({{field.kind|type_in_js_module_with_nullability}}|undefined),
+{%-  endfor %}
+ * } }
+ */
+export const {{union.name}} = {};
diff --git a/chromium/mojo/public/tools/bindings/generators/mojom_cpp_generator.py b/chromium/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
index d73b3f48354..fc7728a1f59 100644
--- a/chromium/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
+++ b/chromium/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
@@ -35,8 +35,6 @@ _kind_to_cpp_literal_suffix = {
 }
 
 
-
-
 class _NameFormatter(object):
   """A formatter for the names of kinds or values."""
 
@@ -268,16 +266,19 @@ class Generator(generator.Generator):
     return used_typemaps
 
   def _GetExtraPublicHeaders(self):
+    headers = set()
+
     all_enums = list(self.module.enums)
     for struct in self.module.structs:
       all_enums.extend(struct.enums)
     for interface in self.module.interfaces:
       all_enums.extend(interface.enums)
+      if interface.uuid:
+        headers.add('base/token.h')
 
     types = set(self._GetFullMojomNameForKind(typename)
                 for typename in
                 self.module.structs + all_enums + self.module.unions)
-    headers = set()
     for typename, typemap in self.typemap.items():
       if typename in types:
         headers.update(typemap.get("public_headers", []))
diff --git a/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py b/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
index 96b2fdfae0c..c51824a444b 100644
--- a/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
+++ b/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
@@ -20,9 +20,12 @@ import mojom.generate.generator as generator
 import mojom.generate.module as mojom
 from mojom.generate.template_expander import UseJinja
 
-sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir,
-                             os.pardir, os.pardir, os.pardir, os.pardir,
-                             'build', 'android', 'gyp'))
+# Item 0 of sys.path is the directory of the main file; item 1 is PYTHONPATH
+# (if set); item 2 is system libraries.
+sys.path.insert(
+    1,
+    os.path.join(os.path.dirname(__file__), os.pardir, os.pardir, os.pardir,
+                 os.pardir, os.pardir, 'build', 'android', 'gyp'))
 from util import build_utils
 
 
diff --git a/chromium/mojo/public/tools/bindings/generators/mojom_js_generator.py b/chromium/mojo/public/tools/bindings/generators/mojom_js_generator.py
index d8e275d83d2..c7068f5d008 100644
--- a/chromium/mojo/public/tools/bindings/generators/mojom_js_generator.py
+++ b/chromium/mojo/public/tools/bindings/generators/mojom_js_generator.py
@@ -1,7 +1,6 @@
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-
 """Generates JavaScript source files from a mojom.Module."""
 
 import mojom.generate.generator as generator
@@ -17,115 +16,115 @@ else:
   import urllib.request as urllib_request
 
 _kind_to_javascript_default_value = {
-  mojom.BOOL:                  "false",
-  mojom.INT8:                  "0",
-  mojom.UINT8:                 "0",
-  mojom.INT16:                 "0",
-  mojom.UINT16:                "0",
-  mojom.INT32:                 "0",
-  mojom.UINT32:                "0",
-  mojom.FLOAT:                 "0",
-  mojom.HANDLE:                "null",
-  mojom.DCPIPE:                "null",
-  mojom.DPPIPE:                "null",
-  mojom.MSGPIPE:               "null",
-  mojom.SHAREDBUFFER:          "null",
-  mojom.PLATFORMHANDLE:          "null",
-  mojom.NULLABLE_HANDLE:       "null",
-  mojom.NULLABLE_DCPIPE:       "null",
-  mojom.NULLABLE_DPPIPE:       "null",
-  mojom.NULLABLE_MSGPIPE:      "null",
-  mojom.NULLABLE_SHAREDBUFFER: "null",
-  mojom.NULLABLE_PLATFORMHANDLE: "null",
-  mojom.INT64:                 "0",
-  mojom.UINT64:                "0",
-  mojom.DOUBLE:                "0",
-  mojom.STRING:                "null",
-  mojom.NULLABLE_STRING:       "null"
+    mojom.BOOL: "false",
+    mojom.INT8: "0",
+    mojom.UINT8: "0",
+    mojom.INT16: "0",
+    mojom.UINT16: "0",
+    mojom.INT32: "0",
+    mojom.UINT32: "0",
+    mojom.FLOAT: "0",
+    mojom.HANDLE: "null",
+    mojom.DCPIPE: "null",
+    mojom.DPPIPE: "null",
+    mojom.MSGPIPE: "null",
+    mojom.SHAREDBUFFER: "null",
+    mojom.PLATFORMHANDLE: "null",
+    mojom.NULLABLE_HANDLE: "null",
+    mojom.NULLABLE_DCPIPE: "null",
+    mojom.NULLABLE_DPPIPE: "null",
+    mojom.NULLABLE_MSGPIPE: "null",
+    mojom.NULLABLE_SHAREDBUFFER: "null",
+    mojom.NULLABLE_PLATFORMHANDLE: "null",
+    mojom.INT64: "0",
+    mojom.UINT64: "0",
+    mojom.DOUBLE: "0",
+    mojom.STRING: "null",
+    mojom.NULLABLE_STRING: "null"
 }
 
 _kind_to_codec_type = {
-  mojom.BOOL:                  "codec.Uint8",
-  mojom.INT8:                  "codec.Int8",
-  mojom.UINT8:                 "codec.Uint8",
-  mojom.INT16:                 "codec.Int16",
-  mojom.UINT16:                "codec.Uint16",
-  mojom.INT32:                 "codec.Int32",
-  mojom.UINT32:                "codec.Uint32",
-  mojom.FLOAT:                 "codec.Float",
-  mojom.HANDLE:                "codec.Handle",
-  mojom.DCPIPE:                "codec.Handle",
-  mojom.DPPIPE:                "codec.Handle",
-  mojom.MSGPIPE:               "codec.Handle",
-  mojom.SHAREDBUFFER:          "codec.Handle",
-  mojom.PLATFORMHANDLE:        "codec.Handle",
-  mojom.NULLABLE_HANDLE:       "codec.NullableHandle",
-  mojom.NULLABLE_DCPIPE:       "codec.NullableHandle",
-  mojom.NULLABLE_DPPIPE:       "codec.NullableHandle",
-  mojom.NULLABLE_MSGPIPE:      "codec.NullableHandle",
-  mojom.NULLABLE_SHAREDBUFFER: "codec.NullableHandle",
-  mojom.NULLABLE_PLATFORMHANDLE: "codec.NullableHandle",
-  mojom.INT64:                 "codec.Int64",
-  mojom.UINT64:                "codec.Uint64",
-  mojom.DOUBLE:                "codec.Double",
-  mojom.STRING:                "codec.String",
-  mojom.NULLABLE_STRING:       "codec.NullableString",
+    mojom.BOOL: "codec.Uint8",
+    mojom.INT8: "codec.Int8",
+    mojom.UINT8: "codec.Uint8",
+    mojom.INT16: "codec.Int16",
+    mojom.UINT16: "codec.Uint16",
+    mojom.INT32: "codec.Int32",
+    mojom.UINT32: "codec.Uint32",
+    mojom.FLOAT: "codec.Float",
+    mojom.HANDLE: "codec.Handle",
+    mojom.DCPIPE: "codec.Handle",
+    mojom.DPPIPE: "codec.Handle",
+    mojom.MSGPIPE: "codec.Handle",
+    mojom.SHAREDBUFFER: "codec.Handle",
+    mojom.PLATFORMHANDLE: "codec.Handle",
+    mojom.NULLABLE_HANDLE: "codec.NullableHandle",
+    mojom.NULLABLE_DCPIPE: "codec.NullableHandle",
+    mojom.NULLABLE_DPPIPE: "codec.NullableHandle",
+    mojom.NULLABLE_MSGPIPE: "codec.NullableHandle",
+    mojom.NULLABLE_SHAREDBUFFER: "codec.NullableHandle",
+    mojom.NULLABLE_PLATFORMHANDLE: "codec.NullableHandle",
+    mojom.INT64: "codec.Int64",
+    mojom.UINT64: "codec.Uint64",
+    mojom.DOUBLE: "codec.Double",
+    mojom.STRING: "codec.String",
+    mojom.NULLABLE_STRING: "codec.NullableString",
 }
 
 _kind_to_closure_type = {
-  mojom.BOOL:                  "boolean",
-  mojom.INT8:                  "number",
-  mojom.UINT8:                 "number",
-  mojom.INT16:                 "number",
-  mojom.UINT16:                "number",
-  mojom.INT32:                 "number",
-  mojom.UINT32:                "number",
-  mojom.FLOAT:                 "number",
-  mojom.INT64:                 "number",
-  mojom.UINT64:                "number",
-  mojom.DOUBLE:                "number",
-  mojom.STRING:                "string",
-  mojom.NULLABLE_STRING:       "string",
-  mojom.HANDLE:                "MojoHandle",
-  mojom.DCPIPE:                "MojoHandle",
-  mojom.DPPIPE:                "MojoHandle",
-  mojom.MSGPIPE:               "MojoHandle",
-  mojom.SHAREDBUFFER:          "MojoHandle",
-  mojom.PLATFORMHANDLE:        "MojoHandle",
-  mojom.NULLABLE_HANDLE:       "MojoHandle",
-  mojom.NULLABLE_DCPIPE:       "MojoHandle",
-  mojom.NULLABLE_DPPIPE:       "MojoHandle",
-  mojom.NULLABLE_MSGPIPE:      "MojoHandle",
-  mojom.NULLABLE_SHAREDBUFFER: "MojoHandle",
-  mojom.NULLABLE_PLATFORMHANDLE: "MojoHandle",
+    mojom.BOOL: "boolean",
+    mojom.INT8: "number",
+    mojom.UINT8: "number",
+    mojom.INT16: "number",
+    mojom.UINT16: "number",
+    mojom.INT32: "number",
+    mojom.UINT32: "number",
+    mojom.FLOAT: "number",
+    mojom.INT64: "number",
+    mojom.UINT64: "number",
+    mojom.DOUBLE: "number",
+    mojom.STRING: "string",
+    mojom.NULLABLE_STRING: "string",
+    mojom.HANDLE: "MojoHandle",
+    mojom.DCPIPE: "MojoHandle",
+    mojom.DPPIPE: "MojoHandle",
+    mojom.MSGPIPE: "MojoHandle",
+    mojom.SHAREDBUFFER: "MojoHandle",
+    mojom.PLATFORMHANDLE: "MojoHandle",
+    mojom.NULLABLE_HANDLE: "MojoHandle",
+    mojom.NULLABLE_DCPIPE: "MojoHandle",
+    mojom.NULLABLE_DPPIPE: "MojoHandle",
+    mojom.NULLABLE_MSGPIPE: "MojoHandle",
+    mojom.NULLABLE_SHAREDBUFFER: "MojoHandle",
+    mojom.NULLABLE_PLATFORMHANDLE: "MojoHandle",
 }
 
 _kind_to_lite_js_type = {
-  mojom.BOOL:                  "mojo.internal.Bool",
-  mojom.INT8:                  "mojo.internal.Int8",
-  mojom.UINT8:                 "mojo.internal.Uint8",
-  mojom.INT16:                 "mojo.internal.Int16",
-  mojom.UINT16:                "mojo.internal.Uint16",
-  mojom.INT32:                 "mojo.internal.Int32",
-  mojom.UINT32:                "mojo.internal.Uint32",
-  mojom.FLOAT:                 "mojo.internal.Float",
-  mojom.HANDLE:                "mojo.internal.Handle",
-  mojom.DCPIPE:                "mojo.internal.Handle",
-  mojom.DPPIPE:                "mojo.internal.Handle",
-  mojom.MSGPIPE:               "mojo.internal.Handle",
-  mojom.SHAREDBUFFER:          "mojo.internal.Handle",
-  mojom.PLATFORMHANDLE:        "mojo.internal.Handle",
-  mojom.NULLABLE_HANDLE:       "mojo.internal.Handle",
-  mojom.NULLABLE_DCPIPE:       "mojo.internal.Handle",
-  mojom.NULLABLE_DPPIPE:       "mojo.internal.Handle",
-  mojom.NULLABLE_MSGPIPE:      "mojo.internal.Handle",
-  mojom.NULLABLE_SHAREDBUFFER: "mojo.internal.Handle",
-  mojom.NULLABLE_PLATFORMHANDLE: "mojo.internal.Handle",
-  mojom.INT64:                 "mojo.internal.Int64",
-  mojom.UINT64:                "mojo.internal.Uint64",
-  mojom.DOUBLE:                "mojo.internal.Double",
-  mojom.STRING:                "mojo.internal.String",
-  mojom.NULLABLE_STRING:       "mojo.internal.String",
+    mojom.BOOL: "mojo.internal.Bool",
+    mojom.INT8: "mojo.internal.Int8",
+    mojom.UINT8: "mojo.internal.Uint8",
+    mojom.INT16: "mojo.internal.Int16",
+    mojom.UINT16: "mojo.internal.Uint16",
+    mojom.INT32: "mojo.internal.Int32",
+    mojom.UINT32: "mojo.internal.Uint32",
+    mojom.FLOAT: "mojo.internal.Float",
+    mojom.HANDLE: "mojo.internal.Handle",
+    mojom.DCPIPE: "mojo.internal.Handle",
+    mojom.DPPIPE: "mojo.internal.Handle",
+    mojom.MSGPIPE: "mojo.internal.Handle",
+    mojom.SHAREDBUFFER: "mojo.internal.Handle",
+    mojom.PLATFORMHANDLE: "mojo.internal.Handle",
+    mojom.NULLABLE_HANDLE: "mojo.internal.Handle",
+    mojom.NULLABLE_DCPIPE: "mojo.internal.Handle",
+    mojom.NULLABLE_DPPIPE: "mojo.internal.Handle",
+    mojom.NULLABLE_MSGPIPE: "mojo.internal.Handle",
+    mojom.NULLABLE_SHAREDBUFFER: "mojo.internal.Handle",
+    mojom.NULLABLE_PLATFORMHANDLE: "mojo.internal.Handle",
+    mojom.INT64: "mojo.internal.Int64",
+    mojom.UINT64: "mojo.internal.Uint64",
+    mojom.DOUBLE: "mojo.internal.Double",
+    mojom.STRING: "mojo.internal.String",
+    mojom.NULLABLE_STRING: "mojo.internal.String",
 }
 
 _js_reserved_keywords = [
@@ -176,34 +175,51 @@ _js_reserved_keywords = [
 ]
 
 _primitive_kind_to_fuzz_type = {
-  mojom.BOOL:                  "Bool",
-  mojom.INT8:                  "Int8",
-  mojom.UINT8:                 "Uint8",
-  mojom.INT16:                 "Int16",
-  mojom.UINT16:                "Uint16",
-  mojom.INT32:                 "Int32",
-  mojom.UINT32:                "Uint32",
-  mojom.FLOAT:                 "Float",
-  mojom.INT64:                 "Int64",
-  mojom.UINT64:                "Uint64",
-  mojom.DOUBLE:                "Double",
-  mojom.STRING:                "String",
-  mojom.NULLABLE_STRING:       "String",
-  mojom.HANDLE:                "Handle",
-  mojom.DCPIPE:                "DataPipeConsumer",
-  mojom.DPPIPE:                "DataPipeProducer",
-  mojom.MSGPIPE:               "MessagePipe",
-  mojom.SHAREDBUFFER:          "SharedBuffer",
-  mojom.PLATFORMHANDLE:        "PlatformHandle",
-  mojom.NULLABLE_HANDLE:       "Handle",
-  mojom.NULLABLE_DCPIPE:       "DataPipeConsumer",
-  mojom.NULLABLE_DPPIPE:       "DataPipeProducer",
-  mojom.NULLABLE_MSGPIPE:      "MessagePipe",
-  mojom.NULLABLE_SHAREDBUFFER: "SharedBuffer",
-  mojom.NULLABLE_PLATFORMHANDLE: "PlatformHandle",
+    mojom.BOOL: "Bool",
+    mojom.INT8: "Int8",
+    mojom.UINT8: "Uint8",
+    mojom.INT16: "Int16",
+    mojom.UINT16: "Uint16",
+    mojom.INT32: "Int32",
+    mojom.UINT32: "Uint32",
+    mojom.FLOAT: "Float",
+    mojom.INT64: "Int64",
+    mojom.UINT64: "Uint64",
+    mojom.DOUBLE: "Double",
+    mojom.STRING: "String",
+    mojom.NULLABLE_STRING: "String",
+    mojom.HANDLE: "Handle",
+    mojom.DCPIPE: "DataPipeConsumer",
+    mojom.DPPIPE: "DataPipeProducer",
+    mojom.MSGPIPE: "MessagePipe",
+    mojom.SHAREDBUFFER: "SharedBuffer",
+    mojom.PLATFORMHANDLE: "PlatformHandle",
+    mojom.NULLABLE_HANDLE: "Handle",
+    mojom.NULLABLE_DCPIPE: "DataPipeConsumer",
+    mojom.NULLABLE_DPPIPE: "DataPipeProducer",
+    mojom.NULLABLE_MSGPIPE: "MessagePipe",
+    mojom.NULLABLE_SHAREDBUFFER: "SharedBuffer",
+    mojom.NULLABLE_PLATFORMHANDLE: "PlatformHandle",
 }
 
 
+_SHARED_MODULE_PREFIX = 'chrome://resources/mojo'
+
+
+def _GetWebUiModulePath(module):
+  """Returns the path to a WebUI module, from the perspective of a WebUI page
+  that makes it available. This is based on the corresponding mojom target's
+  webui_module_path value. Returns None if the target specifies no module
+  path. Otherwise, returned paths always end in a '/' and begin with either
+  `_SHARED_MODULE_PREFIX` or a '/'."""
+  path = module.metadata.get('webui_module_path')
+  if path is None or path == '/':
+    return path
+  if path.startswith(_SHARED_MODULE_PREFIX):
+    return path.rstrip('/') + '/'
+  return '/{}/'.format(path.strip('/'))
+
+
 def JavaScriptPayloadSize(packed):
   packed_fields = packed.packed_fields
   if not packed_fields:
@@ -260,26 +276,46 @@ class JavaScriptStylizer(generator.Stylizer):
     return mojom_name
 
   def StylizeModule(self, mojom_namespace):
-    return '.'.join(generator.ToCamel(word, lower_initial=True)
-                        for word in mojom_namespace.split('.'))
+    return '.'.join(
+        generator.ToCamel(word, lower_initial=True)
+        for word in mojom_namespace.split('.'))
 
 
 class Generator(generator.Generator):
-  def _GetParameters(self, for_compile=False):
+  def _GetParameters(self, for_compile=False, for_webui_module=False):
     return {
-      "enums": self.module.enums,
-      "html_imports": self._GenerateHtmlImports(),
-      "imports": self.module.imports,
-      "interfaces": self.module.interfaces,
-      "kinds": self.module.kinds,
-      "module": self.module,
-      "mojom_filename": os.path.basename(self.module.path),
-      "mojom_namespace": self.module.mojom_namespace,
-      "structs": self.module.structs + self._GetStructsFromMethods(),
-      "unions": self.module.unions,
-      "generate_fuzzing": self.generate_fuzzing,
-      "generate_closure_exports": for_compile,
-      "generate_struct_deserializers": self.js_generate_struct_deserializers,
+        "bindings_library_path":
+        self._GetBindingsLibraryPath(for_webui_module=for_webui_module),
+        "enums":
+        self.module.enums,
+        "for_bindings_internals":
+        self.disallow_native_types,
+        "html_imports":
+        self._GenerateHtmlImports(),
+        "imports":
+        self.module.imports,
+        "interfaces":
+        self.module.interfaces,
+        "js_module_imports":
+        self._GetJsModuleImports(for_webui_module=for_webui_module),
+        "kinds":
+        self.module.kinds,
+        "module":
+        self.module,
+        "mojom_filename":
+        os.path.basename(self.module.path),
+        "mojom_namespace":
+        self.module.mojom_namespace,
+        "structs":
+        self.module.structs + self._GetStructsFromMethods(),
+        "unions":
+        self.module.unions,
+        "generate_fuzzing":
+        self.generate_fuzzing,
+        "generate_closure_exports":
+        for_compile,
+        "generate_struct_deserializers":
+        self.js_generate_struct_deserializers,
     }
 
   @staticmethod
@@ -288,65 +324,75 @@ class Generator(generator.Generator):
 
   def GetFilters(self):
     js_filters = {
-      "closure_type": self._ClosureType,
-      "decode_snippet": self._JavaScriptDecodeSnippet,
-      "default_value": self._JavaScriptDefaultValue,
-      "encode_snippet": self._JavaScriptEncodeSnippet,
-      "expression_to_text": self._ExpressionToText,
-      "expression_to_text_lite": self._ExpressionToTextLite,
-      "field_offset": JavaScriptFieldOffset,
-      "get_relative_url": GetRelativeUrl,
-      "has_callbacks": mojom.HasCallbacks,
-      "is_any_handle_or_interface_kind": mojom.IsAnyHandleOrInterfaceKind,
-      "is_array_kind": mojom.IsArrayKind,
-      "is_associated_interface_kind": mojom.IsAssociatedInterfaceKind,
-      "is_pending_associated_remote_kind": mojom.IsPendingAssociatedRemoteKind,
-      "is_associated_interface_request_kind":
-          mojom.IsAssociatedInterfaceRequestKind,
-      "is_pending_associated_receiver_kind":
-          mojom.IsPendingAssociatedReceiverKind,
-      "is_bool_kind": mojom.IsBoolKind,
-      "is_enum_kind": mojom.IsEnumKind,
-      "is_any_handle_kind": mojom.IsAnyHandleKind,
-      "is_any_interface_kind": mojom.IsAnyInterfaceKind,
-      "is_interface_kind": mojom.IsInterfaceKind,
-      "is_pending_remote_kind": mojom.IsPendingRemoteKind,
-      "is_interface_request_kind": mojom.IsInterfaceRequestKind,
-      "is_pending_receiver_kind": mojom.IsPendingReceiverKind,
-      "is_map_kind": mojom.IsMapKind,
-      "is_object_kind": mojom.IsObjectKind,
-      "is_reference_kind": mojom.IsReferenceKind,
-      "is_string_kind": mojom.IsStringKind,
-      "is_struct_kind": mojom.IsStructKind,
-      "is_union_kind": mojom.IsUnionKind,
-      "js_type": self._JavaScriptType,
-      "lite_default_value": self._LiteJavaScriptDefaultValue,
-      "lite_js_type": self._LiteJavaScriptType,
-      "lite_js_import_name": self._LiteJavaScriptImportName,
-      "method_passes_associated_kinds": mojom.MethodPassesAssociatedKinds,
-      "namespace_declarations": self._NamespaceDeclarations,
-      "closure_type_with_nullability": self._ClosureTypeWithNullability,
-      "lite_closure_param_type": self._LiteClosureParamType,
-      "lite_closure_type": self._LiteClosureType,
-      "lite_closure_type_with_nullability":
-          self._LiteClosureTypeWithNullability,
-      "lite_closure_field_type": self._LiteClosureFieldType,
-      "payload_size": JavaScriptPayloadSize,
-      "to_camel": generator.ToCamel,
-      "union_decode_snippet": self._JavaScriptUnionDecodeSnippet,
-      "union_encode_snippet": self._JavaScriptUnionEncodeSnippet,
-      "validate_array_params": self._JavaScriptValidateArrayParams,
-      "validate_enum_params": self._JavaScriptValidateEnumParams,
-      "validate_map_params": self._JavaScriptValidateMapParams,
-      "validate_nullable_params": self._JavaScriptNullableParam,
-      "validate_struct_params": self._JavaScriptValidateStructParams,
-      "validate_union_params": self._JavaScriptValidateUnionParams,
-      "sanitize_identifier": self._JavaScriptSanitizeIdentifier,
-      "contains_handles_or_interfaces": mojom.ContainsHandlesOrInterfaces,
-      "fuzz_handle_name": self._FuzzHandleName,
-      "is_primitive_kind": self._IsPrimitiveKind,
-      "primitive_to_fuzz_type": self._PrimitiveToFuzzType,
-      "to_js_boolean": self._ToJsBoolean,
+        "closure_type": self._ClosureType,
+        "constant_value": self._GetConstantValue,
+        "constant_value_in_js_module": self._GetConstantValueInJsModule,
+        "decode_snippet": self._JavaScriptDecodeSnippet,
+        "default_value": self._JavaScriptDefaultValue,
+        "default_value_in_js_module": self._DefaultValueInJsModule,
+        "encode_snippet": self._JavaScriptEncodeSnippet,
+        "expression_to_text": self._ExpressionToText,
+        "field_offset": JavaScriptFieldOffset,
+        "field_type_in_js_module": self._GetFieldTypeInJsModule,
+        "get_relative_url": GetRelativeUrl,
+        "has_callbacks": mojom.HasCallbacks,
+        "imports_for_kind": self._GetImportsForKind,
+        "is_any_handle_or_interface_kind": mojom.IsAnyHandleOrInterfaceKind,
+        "is_array_kind": mojom.IsArrayKind,
+        "is_associated_interface_kind": mojom.IsAssociatedInterfaceKind,
+        "is_pending_associated_remote_kind":
+        mojom.IsPendingAssociatedRemoteKind,
+        "is_associated_interface_request_kind":
+        mojom.IsAssociatedInterfaceRequestKind,
+        "is_pending_associated_receiver_kind":
+        mojom.IsPendingAssociatedReceiverKind,
+        "is_bool_kind": mojom.IsBoolKind,
+        "is_enum_kind": mojom.IsEnumKind,
+        "is_any_handle_kind": mojom.IsAnyHandleKind,
+        "is_any_interface_kind": mojom.IsAnyInterfaceKind,
+        "is_interface_kind": mojom.IsInterfaceKind,
+        "is_pending_remote_kind": mojom.IsPendingRemoteKind,
+        "is_interface_request_kind": mojom.IsInterfaceRequestKind,
+        "is_pending_receiver_kind": mojom.IsPendingReceiverKind,
+        "is_map_kind": mojom.IsMapKind,
+        "is_object_kind": mojom.IsObjectKind,
+        "is_reference_kind": mojom.IsReferenceKind,
+        "is_string_kind": mojom.IsStringKind,
+        "is_struct_kind": mojom.IsStructKind,
+        "is_union_kind": mojom.IsUnionKind,
+        "js_type": self._JavaScriptType,
+        "lite_default_value": self._LiteJavaScriptDefaultValue,
+        "lite_js_type": self._LiteJavaScriptType,
+        "lite_js_import_name": self._LiteJavaScriptImportName,
+        "method_passes_associated_kinds": mojom.MethodPassesAssociatedKinds,
+        "namespace_declarations": self._NamespaceDeclarations,
+        "closure_type_with_nullability": self._ClosureTypeWithNullability,
+        "lite_closure_param_type": self._LiteClosureParamType,
+        "lite_closure_type": self._LiteClosureType,
+        "lite_closure_type_with_nullability":
+        self._LiteClosureTypeWithNullability,
+        "lite_closure_field_type": self._LiteClosureFieldType,
+        "param_type_in_js_module": self._GetParamTypeInJsModule,
+        "payload_size": JavaScriptPayloadSize,
+        "spec_type_in_js_module": self._GetSpecTypeInJsModule,
+        "to_camel": generator.ToCamel,
+        "type_in_js_module": self._GetTypeInJsModule,
+        "type_in_js_module_with_nullability":
+        self._GetTypeInJsModuleWithNullability,
+        "union_decode_snippet": self._JavaScriptUnionDecodeSnippet,
+        "union_encode_snippet": self._JavaScriptUnionEncodeSnippet,
+        "validate_array_params": self._JavaScriptValidateArrayParams,
+        "validate_enum_params": self._JavaScriptValidateEnumParams,
+        "validate_map_params": self._JavaScriptValidateMapParams,
+        "validate_nullable_params": self._JavaScriptNullableParam,
+        "validate_struct_params": self._JavaScriptValidateStructParams,
+        "validate_union_params": self._JavaScriptValidateUnionParams,
+        "sanitize_identifier": self._JavaScriptSanitizeIdentifier,
+        "contains_handles_or_interfaces": mojom.ContainsHandlesOrInterfaces,
+        "fuzz_handle_name": self._FuzzHandleName,
+        "is_primitive_kind": self._IsPrimitiveKind,
+        "primitive_to_fuzz_type": self._PrimitiveToFuzzType,
+        "to_js_boolean": self._ToJsBoolean,
     }
     return js_filters
 
@@ -370,6 +416,14 @@ class Generator(generator.Generator):
   def _GenerateLiteBindingsForCompile(self):
     return self._GetParameters(for_compile=True)
 
+  @UseJinja("lite/mojom.m.js.tmpl")
+  def _GenerateJsModule(self):
+    return self._GetParameters()
+
+  @UseJinja("lite/mojom.m.js.tmpl")
+  def _GenerateWebUiModule(self):
+    return self._GetParameters(for_webui_module=True)
+
   def GenerateFiles(self, args):
     if self.variant:
       raise Exception("Variants not supported in JavaScript bindings.")
@@ -391,6 +445,23 @@ class Generator(generator.Generator):
                             "%s-lite.js" % self.module.path)
       self.WriteWithComment(self._GenerateLiteBindingsForCompile(),
                             "%s-lite-for-compile.js" % self.module.path)
+      self.WriteWithComment(self._GenerateJsModule(),
+                            "%s.m.js" % self.module.path)
+      if _GetWebUiModulePath(self.module) is not None:
+        self.WriteWithComment(self._GenerateWebUiModule(),
+                              "mojom-webui/%s-webui.js" % self.module.path)
+
+  def _GetRelativePath(self, path):
+    relpath = urllib_request.pathname2url(
+        os.path.relpath(path, os.path.dirname(self.module.path)))
+    if relpath.startswith('.') or relpath.startswith('/'):
+      return relpath
+    return './' + relpath
+
+  def _GetBindingsLibraryPath(self, for_webui_module=False):
+    if for_webui_module:
+      return "chrome://resources/mojo/mojo/public/js/bindings.js"
+    return self._GetRelativePath('mojo/public/js/bindings.js')
 
   def _SetUniqueNameForImports(self):
     used_names = set()
@@ -416,8 +487,7 @@ class Generator(generator.Generator):
       return kind.module.namespace + "." + kind.name + "Ptr"
     if mojom.IsPendingRemoteKind(kind):
       return kind.kind.module.namespace + "." + kind.kind.name + "Ptr"
-    if (mojom.IsStructKind(kind) or
-        mojom.IsEnumKind(kind)):
+    if (mojom.IsStructKind(kind) or mojom.IsEnumKind(kind)):
       return kind.module.namespace + "." + kind.name
     # TODO(calamity): Support unions properly.
     if mojom.IsUnionKind(kind):
@@ -425,17 +495,17 @@ class Generator(generator.Generator):
     if mojom.IsArrayKind(kind):
       return "Array<%s>" % self._ClosureType(kind.kind)
     if mojom.IsMapKind(kind):
-      return "Map<%s, %s>" % (
-          self._ClosureType(kind.key_kind), self._ClosureType(kind.value_kind))
+      return "Map<%s, %s>" % (self._ClosureType(
+          kind.key_kind), self._ClosureType(kind.value_kind))
     if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(kind):
       return "mojo.InterfaceRequest"
     # TODO(calamity): Support associated interfaces properly.
-    if (mojom.IsAssociatedInterfaceKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind)):
+    if (mojom.IsAssociatedInterfaceKind(kind)
+        or mojom.IsPendingAssociatedRemoteKind(kind)):
       return "mojo.AssociatedInterfacePtrInfo"
     # TODO(calamity): Support associated interface requests properly.
-    if (mojom.IsAssociatedInterfaceRequestKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
+    if (mojom.IsAssociatedInterfaceRequestKind(kind)
+        or mojom.IsPendingAssociatedReceiverKind(kind)):
       return "mojo.AssociatedInterfaceRequest"
     # TODO(calamity): Support enums properly.
 
@@ -445,93 +515,147 @@ class Generator(generator.Generator):
     # Indicates whether a kind of suitable to stringify and use as an Object
     # property name. This is checked for map key types to allow most kinds of
     # mojom maps to be represented as either a Map or an Object.
-    return (mojom.IsIntegralKind(kind) or mojom.IsFloatKind(kind) or
-        mojom.IsDoubleKind(kind) or mojom.IsStringKind(kind) or
-        mojom.IsEnumKind(kind))
-
-  def _LiteClosureType(self, kind):
-    if kind in mojom.PRIMITIVES:
-      return _kind_to_closure_type[kind]
-    if mojom.IsArrayKind(kind):
-      return "Array<%s>" % self._LiteClosureTypeWithNullability(kind.kind)
-    if mojom.IsMapKind(kind) and self._IsStringableKind(kind.key_kind):
-      return "Object<%s, %s>" % (
-          self._LiteClosureTypeWithNullability(kind.key_kind),
-          self._LiteClosureTypeWithNullability(kind.value_kind))
-    if mojom.IsMapKind(kind):
-      return "Map<%s, %s>" % (
-          self._LiteClosureTypeWithNullability(kind.key_kind),
-          self._LiteClosureTypeWithNullability(kind.value_kind))
-
-    if (mojom.IsAssociatedKind(kind) or mojom.IsInterfaceRequestKind(kind) or
-        mojom.IsPendingRemoteKind(kind) or mojom.IsPendingReceiverKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
-      named_kind = kind.kind
-    else:
-      named_kind = kind
-
-    name = []
-    if named_kind.module:
-      name.append(named_kind.module.namespace)
-    if named_kind.parent_kind:
-      name.append(named_kind.parent_kind.name)
+    if kind == mojom.INT64 or kind == mojom.UINT64:
+      # JS BigInts are not stringable and cannot be used as Object property
+      # names.
+      return False
+    return (mojom.IsIntegralKind(kind) or mojom.IsFloatKind(kind)
+            or mojom.IsDoubleKind(kind) or mojom.IsStringKind(kind)
+            or mojom.IsEnumKind(kind))
+
+  def _GetTypeNameForNewBindings(self,
+                                 kind,
+                                 with_nullability=False,
+                                 for_module=False):
+    def recurse_with_nullability(kind):
+      return self._GetTypeNameForNewBindings(kind,
+                                             with_nullability=True,
+                                             for_module=for_module)
+
+    def get_type_name(kind):
+      if kind == mojom.INT64 or kind == mojom.UINT64:
+        return "bigint"
+      if kind in mojom.PRIMITIVES:
+        return _kind_to_closure_type[kind]
+      if mojom.IsArrayKind(kind):
+        return "Array<%s>" % recurse_with_nullability(kind.kind)
+      if mojom.IsMapKind(kind) and self._IsStringableKind(kind.key_kind):
+        return "Object<%s, %s>" % (recurse_with_nullability(
+            kind.key_kind), recurse_with_nullability(kind.value_kind))
+      if mojom.IsMapKind(kind):
+        return "Map<%s, %s>" % (recurse_with_nullability(
+            kind.key_kind), recurse_with_nullability(kind.value_kind))
+
+      if (mojom.IsAssociatedKind(kind) or mojom.IsInterfaceRequestKind(kind)
+          or mojom.IsPendingRemoteKind(kind)
+          or mojom.IsPendingReceiverKind(kind)
+          or mojom.IsPendingAssociatedRemoteKind(kind)
+          or mojom.IsPendingAssociatedReceiverKind(kind)):
+        named_kind = kind.kind
+      else:
+        named_kind = kind
 
-    if mojom.IsEnumKind(kind) and named_kind.parent_kind:
-      name = ".".join(name)
-      name += "_" + named_kind.name
-    else:
-      name.append("" + named_kind.name)
-      name = ".".join(name)
+      name = []
+      qualified = (not for_module) or (self.module is not named_kind.module)
+      if qualified and named_kind.module:
+        name.append(named_kind.module.namespace)
+      if named_kind.parent_kind:
+        name.append(named_kind.parent_kind.name)
+
+      if mojom.IsEnumKind(kind) and named_kind.parent_kind:
+        name = ".".join(name)
+        name += "_" + named_kind.name
+      else:
+        name.append("" + named_kind.name)
+        name = ".".join(name)
+
+      if for_module:
+        name = name.replace(".", "_")
+
+      if (mojom.IsStructKind(kind) or mojom.IsUnionKind(kind)
+          or mojom.IsEnumKind(kind)):
+        return name
+      if mojom.IsInterfaceKind(kind) or mojom.IsPendingRemoteKind(kind):
+        return name + "Remote"
+      if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(
+          kind):
+        return name + "PendingReceiver"
+      # TODO(calamity): Support associated interfaces properly.
+      if (mojom.IsAssociatedInterfaceKind(kind)
+          or mojom.IsPendingAssociatedRemoteKind(kind)):
+        return "Object"
+      # TODO(calamity): Support associated interface requests properly.
+      if (mojom.IsAssociatedInterfaceRequestKind(kind)
+          or mojom.IsPendingAssociatedReceiverKind(kind)):
+        return "Object"
+      raise Exception("No valid closure type: %s" % kind)
+
+    if with_nullability:
+      return ('?' if mojom.IsNullableKind(kind) else '!') + get_type_name(kind)
+
+    return get_type_name(kind)
 
-    if (mojom.IsStructKind(kind) or mojom.IsUnionKind(kind) or
-        mojom.IsEnumKind(kind)):
-      return name
-    if mojom.IsInterfaceKind(kind) or mojom.IsPendingRemoteKind(kind):
-      return name + "Remote"
-    if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(kind):
-      return name + "PendingReceiver"
-    # TODO(calamity): Support associated interfaces properly.
-    if (mojom.IsAssociatedInterfaceKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind)):
-      return "Object"
-    # TODO(calamity): Support associated interface requests properly.
-    if (mojom.IsAssociatedInterfaceRequestKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
-      return "Object"
+  def _LiteClosureType(self, kind):
+    return self._GetTypeNameForNewBindings(kind,
+                                           with_nullability=False,
+                                           for_module=False)
 
-    raise Exception("No valid closure type: %s" % kind)
+  def _GetTypeInJsModule(self, kind):
+    return self._GetTypeNameForNewBindings(kind,
+                                           with_nullability=False,
+                                           for_module=True)
 
   def _ClosureTypeWithNullability(self, kind):
     return ("" if mojom.IsNullableKind(kind) else "!") + self._ClosureType(kind)
 
+  def _GetParamTypeNameForNewBindings(self, kind, for_module=False):
+    def get_type_name(kind):
+      if mojom.IsEnumKind(kind):
+        return "number"
+      prefix = "" if mojom.IsNullableKind(kind) else "!"
+      if mojom.IsArrayKind(kind):
+        return prefix + ("Array<%s>" % get_type_name(kind.kind))
+      if mojom.IsMapKind(kind) and self._IsStringableKind(kind.key_kind):
+        return "(%sMap<%s, %s>|%sObject<%s, %s>)" % (
+            prefix, get_type_name(kind.key_kind), get_type_name(
+                kind.value_kind), prefix, get_type_name(
+                    kind.key_kind), get_type_name(kind.value_kind))
+      if mojom.IsMapKind(kind):
+        return "{}Map<{}, {}>".format(prefix, get_type_name(kind.key_kind),
+                                      get_type_name(kind.value_kind))
+      return prefix + self._GetTypeNameForNewBindings(kind,
+                                                      for_module=for_module)
+
+    return get_type_name(kind)
+
   def _LiteClosureParamType(self, kind):
-    if mojom.IsEnumKind(kind):
-      return "number"
-    prefix = "" if mojom.IsNullableKind(kind) else "!"
-    if mojom.IsStructKind(kind) or mojom.IsUnionKind(kind):
-      return prefix + "Object"
-    if mojom.IsArrayKind(kind):
-      return prefix + ("Array<%s>" %
-                       self._LiteClosureParamType(kind.kind))
-    if mojom.IsMapKind(kind):
-      return "%sMap<%s, %s>|%sObject<%s, %s>" % (
-          prefix, self._LiteClosureParamType(kind.key_kind),
-          self._LiteClosureParamType(kind.value_kind),
-          prefix, self._LiteClosureParamType(kind.key_kind),
-          self._LiteClosureParamType(kind.value_kind))
+    return self._GetParamTypeNameForNewBindings(kind, for_module=False)
 
-    return prefix + self._LiteClosureType(kind)
+  def _GetParamTypeInJsModule(self, kind):
+    return self._GetParamTypeNameForNewBindings(kind, for_module=True)
 
   def _LiteClosureTypeWithNullability(self, kind):
-    return (("?" if mojom.IsNullableKind(kind) else "!") +
-        self._LiteClosureType(kind))
+    return self._GetTypeNameForNewBindings(kind,
+                                           with_nullability=True,
+                                           for_module=False)
 
-  def _LiteClosureFieldType(self, kind):
+  def _GetTypeInJsModuleWithNullability(self, kind):
+    return self._GetTypeNameForNewBindings(kind,
+                                           with_nullability=True,
+                                           for_module=True)
+
+  def _GetFieldTypeForNewBindings(self, kind, for_module=False):
     if mojom.IsNullableKind(kind):
-      return "(" + self._LiteClosureType(kind) + "|undefined)"
+      return "({}|undefined)".format(
+          self._GetTypeNameForNewBindings(kind, for_module=for_module))
     else:
-      return "!" + self._LiteClosureType(kind)
+      return "!" + self._GetTypeNameForNewBindings(kind, for_module=for_module)
+
+  def _LiteClosureFieldType(self, kind):
+    return self._GetFieldTypeForNewBindings(kind, for_module=False)
+
+  def _GetFieldTypeInJsModule(self, kind):
+    return self._GetFieldTypeForNewBindings(kind, for_module=True)
 
   def _NamespaceDeclarations(self, namespace):
     pieces = namespace.split('.')
@@ -542,6 +666,35 @@ class Generator(generator.Generator):
       declarations.append('.'.join(declaration))
     return declarations
 
+  def _GetNameInJsModule(self, kind):
+    qualifier = ""
+    if kind.module is not self.module and kind.module.namespace:
+      qualifier = kind.module.namespace + '.'
+    if kind.parent_kind:
+      qualifier += kind.parent_kind.name + '.'
+    return (qualifier + kind.name).replace('.', '_')
+
+  def _GetImportsForKind(self, kind):
+    qualified_name = self._GetNameInJsModule(kind)
+
+    def make_import(name, suffix=''):
+      class ImportInfo(object):
+        def __init__(self, name, alias):
+          self.name = name
+          self.alias = alias
+
+      return ImportInfo(name + suffix, qualified_name + suffix)
+
+    if (mojom.IsEnumKind(kind) or mojom.IsStructKind(kind)
+        or mojom.IsUnionKind(kind)):
+      return [make_import(kind.name), make_import(kind.name, 'Spec')]
+    if mojom.IsInterfaceKind(kind):
+      return [
+          make_import(kind.name, 'Remote'),
+          make_import(kind.name, 'PendingReceiver')
+      ]
+    assert False, kind.name
+
   def _JavaScriptType(self, kind):
     name = []
     if kind.module and kind.module.path != self.module.path:
@@ -551,55 +704,67 @@ class Generator(generator.Generator):
     name.append(kind.name)
     return ".".join(name)
 
+  def _GetSpecType(self, kind, for_module=False):
+    def get_spec(kind):
+      if self._IsPrimitiveKind(kind):
+        return _kind_to_lite_js_type[kind]
+      if mojom.IsArrayKind(kind):
+        return "mojo.internal.Array(%s, %s)" % (get_spec(
+            kind.kind), "true" if mojom.IsNullableKind(kind.kind) else "false")
+      if mojom.IsMapKind(kind):
+        return "mojo.internal.Map(%s, %s, %s)" % (
+            get_spec(kind.key_kind), get_spec(kind.value_kind),
+            "true" if mojom.IsNullableKind(kind.value_kind) else "false")
+
+      if (mojom.IsAssociatedKind(kind) or mojom.IsInterfaceRequestKind(kind)
+          or mojom.IsPendingRemoteKind(kind)
+          or mojom.IsPendingReceiverKind(kind)
+          or mojom.IsPendingAssociatedRemoteKind(kind)
+          or mojom.IsPendingAssociatedReceiverKind(kind)):
+        named_kind = kind.kind
+      else:
+        named_kind = kind
+
+      name = []
+      qualified = (not for_module) or (self.module is not named_kind.module)
+      if qualified and named_kind.module:
+        name.append(named_kind.module.namespace)
+      if named_kind.parent_kind:
+        parent_name = named_kind.parent_kind.name
+        if mojom.IsStructKind(named_kind.parent_kind) and not for_module:
+          parent_name += "Spec"
+        name.append(parent_name)
+      name.append(named_kind.name)
+      name = ".".join(name)
+      if for_module:
+        name = name.replace(".", "_")
+
+      if (mojom.IsStructKind(kind) or mojom.IsUnionKind(kind)
+          or mojom.IsEnumKind(kind)):
+        return "%sSpec.$" % name
+      if mojom.IsInterfaceKind(kind) or mojom.IsPendingRemoteKind(kind):
+        return "mojo.internal.InterfaceProxy(%sRemote)" % name
+      if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(
+          kind):
+        return "mojo.internal.InterfaceRequest(%sPendingReceiver)" % name
+      if (mojom.IsAssociatedInterfaceKind(kind)
+          or mojom.IsPendingAssociatedRemoteKind(kind)):
+        # TODO(rockot): Implement associated interfaces.
+        return "mojo.internal.AssociatedInterfaceProxy(%sRemote)" % (name)
+      if (mojom.IsAssociatedInterfaceRequestKind(kind)
+          or mojom.IsPendingAssociatedReceiverKind(kind)):
+        return "mojo.internal.AssociatedInterfaceRequest(%sPendingReceiver)" % (
+            name)
+
+      return name
+
+    return get_spec(kind)
+
   def _LiteJavaScriptType(self, kind):
-    if self._IsPrimitiveKind(kind):
-      return _kind_to_lite_js_type[kind]
-    if mojom.IsArrayKind(kind):
-      return "mojo.internal.Array(%s, %s)" % (
-          self._LiteJavaScriptType(kind.kind),
-          "true" if mojom.IsNullableKind(kind.kind) else "false")
-    if mojom.IsMapKind(kind):
-      return "mojo.internal.Map(%s, %s, %s)" % (
-          self._LiteJavaScriptType(kind.key_kind),
-          self._LiteJavaScriptType(kind.value_kind),
-          "true" if mojom.IsNullableKind(kind.value_kind) else "false")
-
-    if (mojom.IsAssociatedKind(kind) or mojom.IsInterfaceRequestKind(kind) or
-        mojom.IsPendingRemoteKind(kind) or mojom.IsPendingReceiverKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
-      named_kind = kind.kind
-    else:
-      named_kind = kind
+    return self._GetSpecType(kind, for_module=False)
 
-    name = []
-    if named_kind.module:
-      name.append(named_kind.module.namespace)
-    if named_kind.parent_kind:
-      parent_name = named_kind.parent_kind.name
-      if mojom.IsStructKind(named_kind.parent_kind):
-        parent_name += "Spec"
-      name.append(parent_name)
-    name.append(named_kind.name)
-    name = ".".join(name)
-
-    if (mojom.IsStructKind(kind) or mojom.IsUnionKind(kind) or
-        mojom.IsEnumKind(kind)):
-      return "%sSpec.$" % name
-    if mojom.IsInterfaceKind(kind) or mojom.IsPendingRemoteKind(kind):
-      return "mojo.internal.InterfaceProxy(%sRemote)" % name
-    if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(kind):
-      return "mojo.internal.InterfaceRequest(%sPendingReceiver)" % name
-    if (mojom.IsAssociatedInterfaceKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind)):
-      # TODO(rockot): Implement associated interfaces.
-      return "mojo.internal.AssociatedInterfaceProxy(%sRemote)" % (name)
-    if (mojom.IsAssociatedInterfaceRequestKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
-      return "mojo.internal.AssociatedInterfaceRequest(%sPendingReceiver)" % (
-        name)
-
-    return name
+  def _GetSpecTypeInJsModule(self, kind):
+    return self._GetSpecType(kind, for_module=True)
 
   def _LiteJavaScriptImportName(self, kind):
     name = []
@@ -630,31 +795,39 @@ class Generator(generator.Generator):
       return "new %sPtr()" % self._JavaScriptType(field.kind)
     if mojom.IsPendingRemoteKind(field.kind):
       return "new %sPtr()" % self._JavaScriptType(field.kind.kind)
-    if (mojom.IsInterfaceRequestKind(field.kind) or
-        mojom.IsPendingReceiverKind(field.kind)):
+    if (mojom.IsInterfaceRequestKind(field.kind)
+        or mojom.IsPendingReceiverKind(field.kind)):
       return "new bindings.InterfaceRequest()"
-    if (mojom.IsAssociatedInterfaceKind(field.kind) or
-        mojom.IsPendingAssociatedRemoteKind(field.kind)):
+    if (mojom.IsAssociatedInterfaceKind(field.kind)
+        or mojom.IsPendingAssociatedRemoteKind(field.kind)):
       return "new associatedBindings.AssociatedInterfacePtrInfo()"
-    if (mojom.IsAssociatedInterfaceRequestKind(field.kind) or
-        mojom.IsPendingAssociatedReceiverKind(field.kind)):
+    if (mojom.IsAssociatedInterfaceRequestKind(field.kind)
+        or mojom.IsPendingAssociatedReceiverKind(field.kind)):
       return "new associatedBindings.AssociatedInterfaceRequest()"
     if mojom.IsEnumKind(field.kind):
       return "0"
     raise Exception("No valid default: %s" % field)
 
-  def _LiteJavaScriptDefaultValue(self, field):
+  def _GetDefaultValue(self, field, for_module=False):
     if field.default:
       if mojom.IsStructKind(field.kind):
         assert field.default == "default"
-        return "null";
-      return self._ExpressionToTextLite(field.default)
+        return "null"
+      return self._ExpressionToTextLite(field.default, for_module=for_module)
+    if field.kind == mojom.INT64 or field.kind == mojom.UINT64:
+      return "BigInt(0)"
     if field.kind in mojom.PRIMITIVES:
       return _kind_to_javascript_default_value[field.kind]
     if mojom.IsEnumKind(field.kind):
       return "0"
     return "null"
 
+  def _LiteJavaScriptDefaultValue(self, field):
+    return self._GetDefaultValue(field, for_module=False)
+
+  def _DefaultValueInJsModule(self, field):
+    return self._GetDefaultValue(field, for_module=True)
+
   def _CodecType(self, kind):
     if kind in mojom.PRIMITIVES:
       return _kind_to_codec_type[kind]
@@ -665,8 +838,8 @@ class Generator(generator.Generator):
     if mojom.IsUnionKind(kind):
       return self._JavaScriptType(kind)
     if mojom.IsArrayKind(kind):
-      array_type = ("NullableArrayOf" if mojom.IsNullableKind(kind)
-                                      else "ArrayOf")
+      array_type = ("NullableArrayOf"
+                    if mojom.IsNullableKind(kind) else "ArrayOf")
       array_length = "" if kind.length is None else ", %d" % kind.length
       element_type = self._ElementCodecType(kind.kind)
       return "new codec.%s(%s%s)" % (array_type, element_type, array_length)
@@ -679,17 +852,18 @@ class Generator(generator.Generator):
           "NullableInterface" if mojom.IsNullableKind(kind) else "Interface",
           self._JavaScriptType(kind.kind))
     if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(kind):
-      return "codec.%s" % (
-          "NullableInterfaceRequest" if mojom.IsNullableKind(kind)
-                                     else "InterfaceRequest")
-    if (mojom.IsAssociatedInterfaceKind(kind) or
-        mojom.IsPendingAssociatedRemoteKind(kind)):
+      return "codec.%s" % ("NullableInterfaceRequest" if
+                           mojom.IsNullableKind(kind) else "InterfaceRequest")
+    if (mojom.IsAssociatedInterfaceKind(kind)
+        or mojom.IsPendingAssociatedRemoteKind(kind)):
       return "codec.%s" % ("NullableAssociatedInterfacePtrInfo"
-          if mojom.IsNullableKind(kind) else "AssociatedInterfacePtrInfo")
-    if (mojom.IsAssociatedInterfaceRequestKind(kind) or
-        mojom.IsPendingAssociatedReceiverKind(kind)):
+                           if mojom.IsNullableKind(kind) else
+                           "AssociatedInterfacePtrInfo")
+    if (mojom.IsAssociatedInterfaceRequestKind(kind)
+        or mojom.IsPendingAssociatedReceiverKind(kind)):
       return "codec.%s" % ("NullableAssociatedInterfaceRequest"
-          if mojom.IsNullableKind(kind) else "AssociatedInterfaceRequest")
+                           if mojom.IsNullableKind(kind) else
+                           "AssociatedInterfaceRequest")
     if mojom.IsEnumKind(kind):
       return "new codec.Enum(%s)" % self._JavaScriptType(kind)
     if mojom.IsMapKind(kind):
@@ -700,19 +874,18 @@ class Generator(generator.Generator):
     raise Exception("No codec type for %s" % kind)
 
   def _ElementCodecType(self, kind):
-    return ("codec.PackedBool" if mojom.IsBoolKind(kind)
-                               else self._CodecType(kind))
+    return ("codec.PackedBool"
+            if mojom.IsBoolKind(kind) else self._CodecType(kind))
 
   def _JavaScriptDecodeSnippet(self, kind):
-    if (kind in mojom.PRIMITIVES or mojom.IsUnionKind(kind) or
-        mojom.IsAnyInterfaceKind(kind)):
+    if (kind in mojom.PRIMITIVES or mojom.IsUnionKind(kind)
+        or mojom.IsAnyInterfaceKind(kind)):
       return "decodeStruct(%s)" % self._CodecType(kind)
     if mojom.IsStructKind(kind):
       return "decodeStructPointer(%s)" % self._JavaScriptType(kind)
     if mojom.IsMapKind(kind):
-      return "decodeMapPointer(%s, %s)" % (
-          self._ElementCodecType(kind.key_kind),
-          self._ElementCodecType(kind.value_kind))
+      return "decodeMapPointer(%s, %s)" % (self._ElementCodecType(
+          kind.key_kind), self._ElementCodecType(kind.value_kind))
     if mojom.IsArrayKind(kind) and mojom.IsBoolKind(kind.kind):
       return "decodeArrayPointer(codec.PackedBool)"
     if mojom.IsArrayKind(kind):
@@ -724,19 +897,18 @@ class Generator(generator.Generator):
     raise Exception("No decode snippet for %s" % kind)
 
   def _JavaScriptEncodeSnippet(self, kind):
-    if (kind in mojom.PRIMITIVES or mojom.IsUnionKind(kind) or
-        mojom.IsAnyInterfaceKind(kind)):
+    if (kind in mojom.PRIMITIVES or mojom.IsUnionKind(kind)
+        or mojom.IsAnyInterfaceKind(kind)):
       return "encodeStruct(%s, " % self._CodecType(kind)
     if mojom.IsUnionKind(kind):
       return "encodeStruct(%s, " % self._JavaScriptType(kind)
     if mojom.IsStructKind(kind):
       return "encodeStructPointer(%s, " % self._JavaScriptType(kind)
     if mojom.IsMapKind(kind):
-      return "encodeMapPointer(%s, %s, " % (
-          self._ElementCodecType(kind.key_kind),
-          self._ElementCodecType(kind.value_kind))
+      return "encodeMapPointer(%s, %s, " % (self._ElementCodecType(
+          kind.key_kind), self._ElementCodecType(kind.value_kind))
     if mojom.IsArrayKind(kind) and mojom.IsBoolKind(kind.kind):
-      return "encodeArrayPointer(codec.PackedBool, ";
+      return "encodeArrayPointer(codec.PackedBool, "
     if mojom.IsArrayKind(kind):
       return "encodeArrayPointer(%s, " % self._CodecType(kind.kind)
     if mojom.IsEnumKind(kind):
@@ -760,8 +932,7 @@ class Generator(generator.Generator):
     nullable = self._JavaScriptNullableParam(field)
     element_kind = field.kind.kind
     element_size = pack.PackedField.GetSizeForKind(element_kind)
-    expected_dimension_sizes = GetArrayExpectedDimensionSizes(
-        field.kind)
+    expected_dimension_sizes = GetArrayExpectedDimensionSizes(field.kind)
     element_type = self._ElementCodecType(element_kind)
     return "%s, %s, %s, %s, 0" % \
         (element_size, element_type, nullable,
@@ -783,7 +954,7 @@ class Generator(generator.Generator):
   def _JavaScriptValidateMapParams(self, field):
     nullable = self._JavaScriptNullableParam(field)
     keys_type = self._ElementCodecType(field.kind.key_kind)
-    values_kind = field.kind.value_kind;
+    values_kind = field.kind.value_kind
     values_type = self._ElementCodecType(values_kind)
     values_nullable = "true" if mojom.IsNullableKind(values_kind) else "false"
     return "%s, %s, %s, %s" % \
@@ -811,23 +982,24 @@ class Generator(generator.Generator):
 
     if isinstance(token, mojom.BuiltinValue):
       if token.value == "double.INFINITY" or token.value == "float.INFINITY":
-        return "Infinity";
+        return "Infinity"
       if token.value == "double.NEGATIVE_INFINITY" or \
          token.value == "float.NEGATIVE_INFINITY":
-        return "-Infinity";
+        return "-Infinity"
       if token.value == "double.NAN" or token.value == "float.NAN":
-        return "NaN";
+        return "NaN"
 
     return token
 
-  def _ExpressionToTextLite(self, token):
+  def _ExpressionToTextLite(self, token, for_module=False):
     if isinstance(token, (mojom.EnumValue, mojom.NamedValue)):
       # Generate the following for:
       #  - Enums: NamespaceUid.Enum.CONSTANT_NAME
       #  - Struct: NamespaceUid.Struct_CONSTANT_NAME
 
       name_prefix = []
-      if token.module:
+      qualified = (not for_module) or (token.module is not self.module)
+      if token.module and qualified:
         name_prefix.append(token.module.namespace)
       if token.parent_kind:
         name_prefix.append(token.parent_kind.name)
@@ -838,20 +1010,72 @@ class Generator(generator.Generator):
       name.append(token.name)
 
       separator = "."
-      if mojom.IsStructKind(token.parent_kind):
+      if mojom.IsStructKind(token.parent_kind) or for_module:
         separator = "_"
 
       return ".".join(name_prefix) + separator + ".".join(name)
 
     return self._ExpressionToText(token)
 
+  def _GetConstantValue(self, constant, for_module=False):
+    assert isinstance(constant, mojom.Constant)
+    text = self._ExpressionToTextLite(constant.value, for_module=for_module)
+    if constant.kind == mojom.INT64 or constant.kind == mojom.UINT64:
+      return "BigInt('{}')".format(text)
+    return text
+
+  def _GetConstantValueInJsModule(self, constant):
+    return self._GetConstantValue(constant, for_module=True)
+
   def _GenerateHtmlImports(self):
     result = []
     for full_import in self.module.imports:
-      result.append(os.path.relpath(full_import.path,
-                                    os.path.dirname(self.module.path)))
+      result.append(
+          os.path.relpath(full_import.path, os.path.dirname(self.module.path)))
     return result
 
+  def _GetJsModuleImports(self, for_webui_module=False):
+    this_module_path = _GetWebUiModulePath(self.module)
+    this_module_is_shared = bool(
+        this_module_path and this_module_path.startswith(_SHARED_MODULE_PREFIX))
+    imports = dict()
+    for spec, kind in self.module.imported_kinds.items():
+      if for_webui_module:
+        assert this_module_path is not None
+        base_path = _GetWebUiModulePath(kind.module)
+        assert base_path is not None
+        import_path = '{}{}-webui.js'.format(base_path,
+                                             os.path.basename(kind.module.path))
+        import_module_is_shared = import_path.startswith(_SHARED_MODULE_PREFIX)
+        if import_module_is_shared == this_module_is_shared:
+          # Either we're a non-shared resource importing another non-shared
+          # resource, or we're a shared resource importing another shared
+          # resource. In both cases, we assume a relative import path will
+          # suffice.
+          def strip_prefix(s, prefix):
+            if s.startswith(prefix):
+              return s[len(prefix):]
+            return s
+
+          import_path = urllib_request.pathname2url(
+              os.path.relpath(
+                  strip_prefix(import_path, _SHARED_MODULE_PREFIX),
+                  strip_prefix(this_module_path, _SHARED_MODULE_PREFIX)))
+          if (not import_path.startswith('.')
+              and not import_path.startswith('/')):
+            import_path = './' + import_path
+        else:
+          assert import_module_is_shared, \
+              'Shared WebUI module "{}" cannot depend on non-shared WebUI ' \
+                  'module "{}"'.format(self.module.path, kind.module.path)
+      else:
+        import_path = self._GetRelativePath(kind.module.path) + '.m.js'
+
+      if import_path not in imports:
+        imports[import_path] = []
+      imports[import_path].append(kind)
+    return imports
+
   def _GetStructsFromMethods(self):
     result = []
     for interface in self.module.interfaces:
@@ -863,20 +1087,17 @@ class Generator(generator.Generator):
 
   def _FuzzHandleName(self, kind):
     if mojom.IsInterfaceRequestKind(kind) or mojom.IsPendingReceiverKind(kind):
-      return '{0}.{1}Request'.format(kind.kind.module.namespace,
-                                     kind.kind.name)
+      return '{0}.{1}Request'.format(kind.kind.module.namespace, kind.kind.name)
     elif mojom.IsInterfaceKind(kind):
-      return '{0}.{1}Ptr'.format(kind.module.namespace,
-                                 kind.name)
+      return '{0}.{1}Ptr'.format(kind.module.namespace, kind.name)
     elif mojom.IsPendingRemoteKind(kind):
-      return '{0}.{1}Ptr'.format(kind.kind.module.namespace,
-                                 kind.kind.name)
-    elif (mojom.IsAssociatedInterfaceRequestKind(kind) or
-          mojom.IsPendingAssociatedReceiverKind(kind)):
+      return '{0}.{1}Ptr'.format(kind.kind.module.namespace, kind.kind.name)
+    elif (mojom.IsAssociatedInterfaceRequestKind(kind)
+          or mojom.IsPendingAssociatedReceiverKind(kind)):
       return '{0}.{1}AssociatedRequest'.format(kind.kind.module.namespace,
                                                kind.kind.name)
-    elif (mojom.IsAssociatedInterfaceKind(kind) or
-          mojom.IsPendingAssociatedRemoteKind(kind)):
+    elif (mojom.IsAssociatedInterfaceKind(kind)
+          or mojom.IsPendingAssociatedRemoteKind(kind)):
       return '{0}.{1}AssociatedPtr'.format(kind.kind.module.namespace,
                                            kind.kind.name)
     elif mojom.IsSharedBufferKind(kind):
diff --git a/chromium/mojo/public/tools/bindings/mojom.gni b/chromium/mojo/public/tools/bindings/mojom.gni
index a676fae5d22..8106c57ea0c 100644
--- a/chromium/mojo/public/tools/bindings/mojom.gni
+++ b/chromium/mojo/public/tools/bindings/mojom.gni
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
 import("//third_party/closure_compiler/closure_args.gni")
 import("//third_party/closure_compiler/compile_js.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ -77,7 +78,6 @@ mojom_parser_sources = [
   "$_mojom_library_root/__init__.py",
   "$_mojom_library_root/error.py",
   "$_mojom_library_root/generate/__init__.py",
-  "$_mojom_library_root/generate/constant_resolver.py",
   "$_mojom_library_root/generate/generator.py",
   "$_mojom_library_root/generate/module.py",
   "$_mojom_library_root/generate/pack.py",
@@ -291,6 +291,21 @@ if (enable_scrambled_message_ids) {
 #       List of extra C++ templates that are used to generate additional source
 #       and/or header files. The templates should end with extension ".tmpl".
 #
+#   webui_module_path (optional)
+#       The path or URL at which modules generated by this target will be
+#       accessible to WebUI pages. This may either be an absolute path or
+#       a full URL path starting with "chrome://resources/mojo".
+#
+#       If an absolute path, a WebUI page may only import these modules if
+#       they are manually packaged and mapped independently by that page's
+#       WebUIDataSource. The mapped path must match the path given here.
+#
+#       If this is is instead a URL string starting with
+#       "chrome://resources/mojo", the generated resources must be added to
+#       content_resources.grd and registered with
+#       content::SharedResourcesDataSource with a corresponding path, at which
+#       point they will be made available to all WebUI pages at the given URL.
+#
 # The following parameters are used to support the component build. They are
 # needed so that bindings which are linked with a component can use the same
 # export settings for classes. The first three are for the chromium variant, and
@@ -500,12 +515,6 @@ template("mojom") {
     sources_list = invoker.sources
   }
 
-  # Reset sources_assignment_filter for the BUILD.gn file to prevent
-  # regression during the migration of Chromium away from the feature.
-  # See docs/no_sources_assignment_filter.md for more information.
-  # TODO(crbug.com/1018739): remove this when migration is done.
-  set_sources_assignment_filter([])
-
   # Listed sources may be relative to the current target dir, or they may be
   # absolute paths, including paths to generated mojom files. While those are
   # fine as-is for input references, deriving output paths can be more subtle.
@@ -621,7 +630,8 @@ template("mojom") {
       enabled_features += [ "is_win" ]
     }
 
-    action(parser_target_name) {
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(parser_target_name) {
       script = mojom_parser_script
       inputs = mojom_parser_sources + [ build_metadata_filename ]
       sources = sources_list
@@ -643,7 +653,7 @@ template("mojom") {
         # Resolve relative input mojom paths against both the root src dir and
         # the root gen dir.
         "--input-root",
-        rebase_path("//"),
+        rebase_path("//."),
         "--input-root",
         rebase_path(root_gen_dir),
 
@@ -662,6 +672,13 @@ template("mojom") {
           enabled_feature,
         ]
       }
+
+      if (defined(invoker.webui_module_path)) {
+        args += [
+          "--add-module-metadata",
+          "webui_module_path=${invoker.webui_module_path}",
+        ]
+      }
     }
   }
 
@@ -731,7 +748,8 @@ template("mojom") {
       }
     }
 
-    action(generator_cpp_message_ids_target_name) {
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(generator_cpp_message_ids_target_name) {
       script = mojom_generator_script
       inputs = mojom_generator_sources + jinja2_sources
       sources = sources_list
@@ -770,7 +788,9 @@ template("mojom") {
     }
 
     generator_shared_target_name = "${target_name}_shared__generator"
-    action(generator_shared_target_name) {
+
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(generator_shared_target_name) {
       visibility = [ ":*" ]
       script = mojom_generator_script
       inputs = mojom_generator_sources + jinja2_sources
@@ -889,7 +909,9 @@ template("mojom") {
 
     generator_mojolpm_proto_target_name =
         "${target_name}_mojolpm_proto_generator"
-    action(generator_mojolpm_proto_target_name) {
+
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(generator_mojolpm_proto_target_name) {
       script = mojom_generator_script
       inputs = mojom_generator_sources + jinja2_sources
       sources = invoker.sources
@@ -1078,7 +1100,9 @@ template("mojom") {
       ]
 
       generator_target_name = "${target_name}${variant_suffix}__generator"
-      action(generator_target_name) {
+
+      # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+      python2_action(generator_target_name) {
         visibility = [ ":*" ]
         script = mojom_generator_script
         inputs = mojom_generator_sources + jinja2_sources
@@ -1258,7 +1282,9 @@ template("mojom") {
     }
     write_file(_typemap_config_filename, _rebased_typemap_configs, "json")
     _mojom_target_name = target_name
-    action(_typemap_validator_target_name) {
+
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(_typemap_validator_target_name) {
       script = "$mojom_generator_root/validate_typemap_config.py"
       inputs = [ _typemap_config_filename ]
       outputs = [ _typemap_stamp_filename ]
@@ -1269,7 +1295,8 @@ template("mojom") {
       ]
     }
 
-    action(type_mappings_target_name) {
+    # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+    python2_action(type_mappings_target_name) {
       inputs =
           mojom_generator_sources + jinja2_sources + [ _typemap_stamp_filename ]
       outputs = [ type_mappings_path ]
@@ -1319,6 +1346,10 @@ template("mojom") {
         full_name = get_label_info("$d", "label_no_toolchain")
         public_deps += [ "${full_name}${variant_suffix}_headers" ]
       }
+      if (defined(bindings_configuration.for_blink) &&
+          bindings_configuration.for_blink) {
+        public_deps += [ "//mojo/public/cpp/bindings:wtf_support" ]
+      }
     }
 
     if (!force_source_set && defined(invoker.component_macro_prefix)) {
@@ -1438,7 +1469,8 @@ template("mojom") {
 
       java_generator_target_name = target_name + "_java__generator"
       if (sources_list != []) {
-        action(java_generator_target_name) {
+        # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+        python2_action(java_generator_target_name) {
           script = mojom_generator_script
           inputs = mojom_generator_sources + jinja2_sources
           sources = sources_list
@@ -1477,7 +1509,9 @@ template("mojom") {
       }
 
       java_srcjar_target_name = target_name + "_java_sources"
-      action(java_srcjar_target_name) {
+
+      # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+      python2_action(java_srcjar_target_name) {
         script = "//build/android/gyp/zip.py"
         inputs = []
         if (output_file_base_paths != []) {
@@ -1536,7 +1570,9 @@ template("mojom") {
       !use_typescript_for_target) {
     if (sources_list != []) {
       generator_js_target_name = "${target_name}_js__generator"
-      action(generator_js_target_name) {
+
+      # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+      python2_action(generator_js_target_name) {
         script = mojom_generator_script
         inputs = mojom_generator_sources + jinja2_sources
         sources = sources_list
@@ -1557,10 +1593,15 @@ template("mojom") {
           outputs += [
             "$root_gen_dir/$base_path.js",
             "$root_gen_dir/$base_path.externs.js",
+            "$root_gen_dir/$base_path.m.js",
             "$root_gen_dir/$base_path-lite.js",
             "$root_gen_dir/$base_path.html",
             "$root_gen_dir/$base_path-lite-for-compile.js",
           ]
+
+          if (defined(invoker.webui_module_path)) {
+            outputs += [ "$root_gen_dir/mojom-webui/$base_path-webui.js" ]
+          }
         }
 
         response_file_contents = filelist
@@ -1609,13 +1650,19 @@ template("mojom") {
         foreach(base_path, output_file_base_paths) {
           data += [
             "$root_gen_dir/${base_path}.js",
+            "$root_gen_dir/${base_path}.m.js",
             "$root_gen_dir/${base_path}-lite.js",
           ]
         }
         deps += [ ":$generator_js_target_name" ]
       }
 
-      data_deps = []
+      if (defined(invoker.disallow_native_types) &&
+          invoker.disallow_native_types) {
+        data_deps = []
+      } else {
+        data_deps = [ "//mojo/public/js:bindings_module" ]
+      }
       foreach(d, all_deps) {
         full_name = get_label_info(d, "label_no_toolchain")
         data_deps += [ "${full_name}_js_data_deps" ]
@@ -1671,6 +1718,64 @@ template("mojom") {
       group(js_library_for_compile_target_name) {
       }
     }
+
+    js_modules_target_name = "${target_name}_js_modules"
+    if (sources_list != []) {
+      js_library(js_modules_target_name) {
+        extra_public_deps = [ ":$generator_js_target_name" ]
+        sources = []
+        foreach(base_path, output_file_base_paths) {
+          sources += [ "$root_gen_dir/${base_path}.m.js" ]
+        }
+        externs_list = [
+          "${externs_path}/mojo_core.js",
+          "${externs_path}/pending.js",
+        ]
+        if (defined(invoker.disallow_native_types) &&
+            invoker.disallow_native_types) {
+          deps = []
+        } else {
+          deps = [ "//mojo/public/js:bindings_uncompiled" ]
+        }
+        foreach(d, all_deps) {
+          full_name = get_label_info(d, "label_no_toolchain")
+          deps += [ "${full_name}_js_modules" ]
+        }
+      }
+    } else {
+      group(js_modules_target_name) {
+      }
+    }
+
+    if (defined(invoker.webui_module_path)) {
+      webui_js_target_name = "${target_name}_webui_js"
+      if (sources_list != []) {
+        js_library(webui_js_target_name) {
+          extra_public_deps = [ ":$generator_js_target_name" ]
+          sources = []
+          foreach(base_path, output_file_base_paths) {
+            sources += [ "$root_gen_dir/mojom-webui/${base_path}-webui.js" ]
+          }
+          externs_list = [
+            "${externs_path}/mojo_core.js",
+            "${externs_path}/pending.js",
+          ]
+          if (defined(invoker.disallow_native_types) &&
+              invoker.disallow_native_types) {
+            deps = []
+          } else {
+            deps = [ "//mojo/public/js:bindings_uncompiled" ]
+          }
+          foreach(d, all_deps) {
+            full_name = get_label_info(d, "label_no_toolchain")
+            deps += [ "${full_name}_webui_js" ]
+          }
+        }
+      } else {
+        group(webui_js_target_name) {
+        }
+      }
+    }
   }
   if ((generate_fuzzing || !defined(invoker.cpp_only) || !invoker.cpp_only) &&
       use_typescript_for_target) {
@@ -1707,7 +1812,9 @@ template("mojom") {
       # Generate Typescript bindings.
       generator_ts_target_name =
           "${target_name}_${dependency_type.name}__ts__generator"
-      action(generator_ts_target_name) {
+
+      # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+      python2_action(generator_ts_target_name) {
         script = mojom_generator_script
         inputs = mojom_generator_sources + jinja2_sources
         sources = sources_list
@@ -1774,7 +1881,8 @@ template("mojom") {
           "${target_name}_${dependency_type.name}__js__generator"
       generator_js_target_names += [ generator_js_target_name ]
 
-      action(generator_js_target_name) {
+      # TODO(crbug.com/1112471): Get this to run cleanly under Python 3.
+      python2_action(generator_js_target_name) {
         script = "$mojom_generator_root/compile_typescript.py"
         sources = ts_outputs
         outputs = js_outputs
diff --git a/chromium/mojo/public/tools/mojom/mojom/BUILD.gn b/chromium/mojo/public/tools/mojom/mojom/BUILD.gn
index 7416ef19e3e..51facc0ccb8 100644
--- a/chromium/mojo/public/tools/mojom/mojom/BUILD.gn
+++ b/chromium/mojo/public/tools/mojom/mojom/BUILD.gn
@@ -8,7 +8,6 @@ group("mojom") {
     "error.py",
     "fileutil.py",
     "generate/__init__.py",
-    "generate/constant_resolver.py",
     "generate/generator.py",
     "generate/module.py",
     "generate/pack.py",
diff --git a/chromium/mojo/public/tools/mojom/mojom/generate/constant_resolver.py b/chromium/mojo/public/tools/mojom/mojom/generate/constant_resolver.py
deleted file mode 100644
index 0dfd996e355..00000000000
--- a/chromium/mojo/public/tools/mojom/mojom/generate/constant_resolver.py
+++ /dev/null
@@ -1,93 +0,0 @@
-# Copyright 2015 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-"""Resolves the values used for constants and enums."""
-
-from itertools import ifilter
-
-from mojom.generate import module as mojom
-
-
-def ResolveConstants(module, expression_to_text):
-  in_progress = set()
-  computed = set()
-
-  def GetResolvedValue(named_value):
-    assert isinstance(named_value, (mojom.EnumValue, mojom.ConstantValue))
-    if isinstance(named_value, mojom.EnumValue):
-      field = next(
-          ifilter(lambda field: field.name == named_value.name,
-                  named_value.enum.fields), None)
-      if not field:
-        raise RuntimeError(
-            'Unable to get computed value for field %s of enum %s' %
-            (named_value.name, named_value.enum.name))
-      if field not in computed:
-        ResolveEnum(named_value.enum)
-      return field.resolved_value
-    else:
-      ResolveConstant(named_value.constant)
-      named_value.resolved_value = named_value.constant.resolved_value
-      return named_value.resolved_value
-
-  def ResolveConstant(constant):
-    if constant in computed:
-      return
-    if constant in in_progress:
-      raise RuntimeError('Circular dependency for constant: %s' % constant.name)
-    in_progress.add(constant)
-    if isinstance(constant.value, (mojom.EnumValue, mojom.ConstantValue)):
-      resolved_value = GetResolvedValue(constant.value)
-    else:
-      resolved_value = expression_to_text(constant.value)
-    constant.resolved_value = resolved_value
-    in_progress.remove(constant)
-    computed.add(constant)
-
-  def ResolveEnum(enum):
-    def ResolveEnumField(enum, field, default_value):
-      if field in computed:
-        return
-      if field in in_progress:
-        raise RuntimeError('Circular dependency for enum: %s' % enum.name)
-      in_progress.add(field)
-      if field.value:
-        if isinstance(field.value, mojom.EnumValue):
-          resolved_value = GetResolvedValue(field.value)
-        elif isinstance(field.value, str):
-          resolved_value = int(field.value, 0)
-        else:
-          raise RuntimeError('Unexpected value: %s' % field.value)
-      else:
-        resolved_value = default_value
-      field.resolved_value = resolved_value
-      in_progress.remove(field)
-      computed.add(field)
-
-    current_value = 0
-    for field in enum.fields:
-      ResolveEnumField(enum, field, current_value)
-      current_value = field.resolved_value + 1
-
-  for constant in module.constants:
-    ResolveConstant(constant)
-
-  for enum in module.enums:
-    ResolveEnum(enum)
-
-  for struct in module.structs:
-    for constant in struct.constants:
-      ResolveConstant(constant)
-    for enum in struct.enums:
-      ResolveEnum(enum)
-    for field in struct.fields:
-      if isinstance(field.default, (mojom.ConstantValue, mojom.EnumValue)):
-        field.default.resolved_value = GetResolvedValue(field.default)
-
-  for interface in module.interfaces:
-    for constant in interface.constants:
-      ResolveConstant(constant)
-    for enum in interface.enums:
-      ResolveEnum(enum)
-
-  return module
diff --git a/chromium/mojo/public/tools/mojom/mojom/generate/module.py b/chromium/mojo/public/tools/mojom/mojom/generate/module.py
index ebbc9b322ea..e76f66a8d24 100644
--- a/chromium/mojo/public/tools/mojom/mojom/generate/module.py
+++ b/chromium/mojo/public/tools/mojom/mojom/generate/module.py
@@ -13,6 +13,7 @@
 # method.AddParameter('baz', 0, mojom.INT32)
 
 import pickle
+from uuid import UUID
 
 
 class BackwardCompatibilityChecker(object):
@@ -286,6 +287,7 @@ ATTRIBUTE_EXTENSIBLE = 'Extensible'
 ATTRIBUTE_STABLE = 'Stable'
 ATTRIBUTE_SYNC = 'Sync'
 ATTRIBUTE_UNLIMITED_SIZE = 'UnlimitedSize'
+ATTRIBUTE_UUID = 'Uuid'
 
 
 class NamedValue(object):
@@ -1188,6 +1190,20 @@ class Interface(ReferenceKind):
                  self.attributes) == (rhs.mojom_name, rhs.methods, rhs.enums,
                                       rhs.constants, rhs.attributes))
 
+  @property
+  def uuid(self):
+    uuid_str = self.attributes.get(ATTRIBUTE_UUID) if self.attributes else None
+    if uuid_str is None:
+      return None
+
+    try:
+      u = UUID(uuid_str)
+    except:
+      raise ValueError('Invalid format for Uuid attribute on interface {}. '
+                       'Expected standard RFC 4122 string representation of '
+                       'a UUID.'.format(self.mojom_name))
+    return (int(u.hex[:16], 16), int(u.hex[16:], 16))
+
   def __hash__(self):
     return id(self)
 
@@ -1346,6 +1362,7 @@ class Module(object):
     self.attributes = attributes
     self.imports = []
     self.imported_kinds = {}
+    self.metadata = {}
 
   def __repr__(self):
     # Gives us a decent __repr__ for modules.
diff --git a/chromium/mojo/public/tools/mojom/mojom_parser.py b/chromium/mojo/public/tools/mojom/mojom_parser.py
index 12adbfb9d3f..998304c3c99 100755
--- a/chromium/mojo/public/tools/mojom/mojom_parser.py
+++ b/chromium/mojo/public/tools/mojom/mojom_parser.py
@@ -98,7 +98,7 @@ def _GetModuleFilename(mojom_filename):
 
 
 def _EnsureInputLoaded(mojom_abspath, module_path, abs_paths, asts,
-                       dependencies, loaded_modules):
+                       dependencies, loaded_modules, module_metadata):
   """Recursively ensures that a module and its dependencies are loaded.
 
   Args:
@@ -111,10 +111,8 @@ def _EnsureInputLoaded(mojom_abspath, module_path, abs_paths, asts,
         by absolute file path.
     loaded_modules: A mapping of all modules loaded so far, including non-input
         modules that were pulled in as transitive dependencies of the inputs.
-    import_set: The working set of mojom imports processed so far in this
-        call stack. Used to detect circular dependencies.
-    import_stack: An ordered list of imports processed so far in this call
-        stack. Used to report circular dependencies.
+    module_metadata: Metadata to be attached to every module loaded by this
+        helper.
 
   Returns:
     None
@@ -129,7 +127,7 @@ def _EnsureInputLoaded(mojom_abspath, module_path, abs_paths, asts,
   for dep_abspath, dep_path in dependencies[mojom_abspath]:
     if dep_abspath not in loaded_modules:
       _EnsureInputLoaded(dep_abspath, dep_path, abs_paths, asts, dependencies,
-                         loaded_modules)
+                         loaded_modules, module_metadata)
 
   imports = {}
   for imp in asts[mojom_abspath].import_list:
@@ -137,6 +135,7 @@ def _EnsureInputLoaded(mojom_abspath, module_path, abs_paths, asts,
     imports[path] = loaded_modules[abs_paths[path]]
   loaded_modules[mojom_abspath] = translate.OrderedModule(
       asts[mojom_abspath], module_path, imports)
+  loaded_modules[mojom_abspath].metadata = dict(module_metadata)
 
 
 def _CollectAllowedImportsFromBuildMetadata(build_metadata_filename):
@@ -161,6 +160,7 @@ def _ParseMojoms(mojom_files,
                  input_root_paths,
                  output_root_path,
                  enabled_features,
+                 module_metadata,
                  allowed_imports=None):
   """Parses a set of mojom files and produces serialized module outputs.
 
@@ -176,6 +176,8 @@ def _ParseMojoms(mojom_files,
         modules for any transitive dependencies not listed in mojom_files.
     enabled_features: A list of enabled feature names, controlling which AST
         nodes are filtered by [EnableIf] attributes.
+    module_metadata: A list of 2-tuples representing metadata key-value pairs to
+        attach to each compiled module output.
 
   Returns:
     None.
@@ -236,7 +238,7 @@ def _ParseMojoms(mojom_files,
   num_existing_modules_loaded = len(loaded_modules)
   for mojom_abspath, mojom_path in mojom_files_to_parse.items():
     _EnsureInputLoaded(mojom_abspath, mojom_path, abs_paths, loaded_mojom_asts,
-                       input_dependencies, loaded_modules)
+                       input_dependencies, loaded_modules, module_metadata)
   assert (num_existing_modules_loaded +
           len(mojom_files_to_parse) == len(loaded_modules))
 
@@ -333,6 +335,16 @@ already present in the provided output root.""")
       'build-time dependency checking for mojom imports, where each build '
       'metadata file corresponds to a build target in the dependency graph of '
       'a typical build system.')
+  arg_parser.add_argument(
+      '--add-module-metadata',
+      dest='module_metadata',
+      default=[],
+      action='append',
+      metavar='KEY=VALUE',
+      help='Adds a metadata key-value pair to the output module. This can be '
+      'used by build toolchains to augment parsed mojom modules with product-'
+      'specific metadata for later extraction and use by custom bindings '
+      'generators.')
 
   args, _ = arg_parser.parse_known_args(command_line)
   if args.mojom_file_list:
@@ -353,8 +365,9 @@ already present in the provided output root.""")
   else:
     allowed_imports = None
 
+  module_metadata = map(lambda kvp: tuple(kvp.split('=')), args.module_metadata)
   _ParseMojoms(mojom_files, input_roots, output_root, args.enabled_features,
-               allowed_imports)
+               module_metadata, allowed_imports)
 
 
 if __name__ == '__main__':