BASELINE: Update Chromium to 71.0.3578.93

Change-Id: I6a32086c33670e1b033f8b10e6bf1fd4da1d105d
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

18 files changed, 307 insertions, 261 deletions

diff --git a/chromium/components/update_client/BUILD.gn b/chromium/components/update_client/BUILD.gn
index 966e7346891..0c6ef0f6082 100644
--- a/chromium/components/update_client/BUILD.gn
+++ b/chromium/components/update_client/BUILD.gn
@@ -185,5 +185,6 @@ source_set("unit_tests") {
     "//testing/gmock",
     "//testing/gtest",
     "//third_party/libxml",
+    "//third_party/re2",
   ]
 }
diff --git a/chromium/components/update_client/DEPS b/chromium/components/update_client/DEPS
index 11fec055972..7beeb7b82cb 100644
--- a/chromium/components/update_client/DEPS
+++ b/chromium/components/update_client/DEPS
@@ -15,5 +15,6 @@ include_rules = [
   "+services/network/test",
   "+services/service_manager/public",
   "+third_party/libxml",
+  "+third_party/re2",
   "+third_party/zlib",
 ]
diff --git a/chromium/components/update_client/configurator.h b/chromium/components/update_client/configurator.h
index db2762fe4f1..347813e4832 100644
--- a/chromium/components/update_client/configurator.h
+++ b/chromium/components/update_client/configurator.h
@@ -9,6 +9,7 @@
 #include <string>
 #include <vector>
 
+#include "base/containers/flat_map.h"
 #include "base/memory/ref_counted.h"
 #include "services/network/public/cpp/shared_url_loader_factory.h"
 
@@ -82,9 +83,9 @@ class Configurator : public base::RefCountedThreadSafe<Configurator> {
   virtual std::string GetOSLongName() const = 0;
 
   // Parameters added to each url request. It can be empty if none are needed.
-  // The return string must be safe for insertion as an attribute in an
-  // XML element.
-  virtual std::string ExtraRequestParams() const = 0;
+  // Returns a map of name-value pairs that match ^[-_a-zA-Z0-9]$ regex.
+  virtual base::flat_map<std::string, std::string> ExtraRequestParams()
+      const = 0;
 
   // Provides a hint for the server to control the order in which multiple
   // download urls are returned. The hint may or may not be honored in the
diff --git a/chromium/components/update_client/ping_manager_unittest.cc b/chromium/components/update_client/ping_manager_unittest.cc
index 3e0b9db9142..0ac9f80b475 100644
--- a/chromium/components/update_client/ping_manager_unittest.cc
+++ b/chromium/components/update_client/ping_manager_unittest.cc
@@ -22,6 +22,7 @@
 #include "components/update_client/url_loader_post_interceptor.h"
 #include "net/url_request/url_request_test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/re2/src/re2/re2.h"
 
 using std::string;
 
@@ -123,13 +124,22 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos,
-              interceptor->GetRequestBody(0).find(
-                  "<app appid=\"abc\">"
-                  "<event eventtype=\"3\" eventresult=\"1\" "
-                  "previousversion=\"1.0\" nextversion=\"2.0\"/></app>"))
-        << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos, interceptor->GetRequestBody(0).find(" sessionid="));
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<\?xml version="1\.0" encoding="UTF-8"\?>)"
+        R"(<request protocol="3\.1" )"
+        R"(dedup="cr" acceptformat="crx2,crx3" )"
+        R"(sessionid="{[-\w]{36}}" requestid="{[-\w]{36}}" )"
+        R"(updater="fake_prodid" updaterversion="30\.0" prodversion="30\.0" )"
+        R"(lang="fake_lang" updaterchannel="fake_channel_string" )"
+        R"(prodchannel="fake_channel_string" )"
+        R"(os="\w+" arch="\w+" nacl_arch="[-\w]+"( wow64="1")?>)"
+        R"(<hw physmemory="\d+"/>)"
+        R"(<os platform="Fake Operating System" arch="[,-.\w]+" )"
+        R"(version="[-.\w]+"( sp="[\s\w]+")?/>)"
+        R"(<app appid="abc"><event eventtype="3" eventresult="1" )"
+        R"(previousversion="1\.0" nextversion="2\.0"/></app></request>)";
+    EXPECT_TRUE(RE2::FullMatch(msg, regex)) << msg;
 
     // Check the ping request does not carry the specific extra request headers.
     EXPECT_FALSE(std::get<1>(interceptor->GetRequests()[0])
@@ -157,12 +167,11 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos,
-              interceptor->GetRequestBody(0).find(
-                  "<app appid=\"abc\">"
-                  "<event eventtype=\"3\" eventresult=\"0\" "
-                  "previousversion=\"1.0\" nextversion=\"2.0\"/></app>"))
-        << interceptor->GetRequestsAsString();
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<app appid="abc"><event eventtype="3" eventresult="0" )"
+        R"(previousversion="1\.0" nextversion="2\.0"/></app>)";
+    EXPECT_TRUE(RE2::PartialMatch(msg, regex)) << msg;
     interceptor->Reset();
   }
 
@@ -190,16 +199,16 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos,
-              interceptor->GetRequestBody(0).find(
-                  "<app appid=\"abc\">"
-                  "<event eventtype=\"3\" eventresult=\"0\" errorcat=\"1\" "
-                  "errorcode=\"2\" extracode1=\"-1\" diffresult=\"0\" "
-                  "differrorcat=\"4\" "
-                  "differrorcode=\"20\" diffextracode1=\"-10\" "
-                  "previousfp=\"prev fp\" nextfp=\"next fp\" "
-                  "previousversion=\"1.0\" nextversion=\"2.0\"/></app>"))
-        << interceptor->GetRequestsAsString();
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<app appid="abc">)"
+        R"(<event eventtype="3" eventresult="0" errorcat="1" )"
+        R"(errorcode="2" extracode1="-1" diffresult="0" )"
+        R"(differrorcat="4" differrorcode="20" diffextracode1="-10" )"
+        R"(previousfp="prev fp" nextfp="next fp" )"
+        R"(previousversion="1\.0" nextversion="2\.0"/></app>)";
+    EXPECT_TRUE(RE2::PartialMatch(msg, regex)) << msg;
+
     interceptor->Reset();
   }
 
@@ -218,11 +227,12 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos,
-              interceptor->GetRequestBody(0).find(
-                  "<app appid=\"abc\"><event eventtype=\"3\" eventresult=\"0\" "
-                  "previousversion=\"1.0\"/></app>"))
-        << interceptor->GetRequestsAsString();
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<app appid="abc"><event eventtype="3" eventresult="0" )"
+        R"(previousversion="1\.0"/></app>)";
+    EXPECT_TRUE(RE2::PartialMatch(msg, regex)) << msg;
+
     interceptor->Reset();
   }
 
@@ -239,12 +249,12 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(string::npos,
-              interceptor->GetRequestBody(0).find(
-                  "<app appid=\"abc\">"
-                  "<event eventtype=\"4\" eventresult=\"1\" "
-                  "previousversion=\"1.2.3.4\" nextversion=\"0\"/></app>"))
-        << interceptor->GetRequestsAsString();
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<app appid="abc"><event eventtype="4" eventresult="1" )"
+        R"(previousversion="1\.2\.3\.4" nextversion="0"/></app>)";
+    EXPECT_TRUE(RE2::PartialMatch(msg, regex)) << msg;
+
     interceptor->Reset();
   }
 
@@ -282,21 +292,21 @@ TEST_F(PingManagerTest, SendPing) {
     RunThreads();
 
     EXPECT_EQ(1, interceptor->GetCount()) << interceptor->GetRequestsAsString();
-    EXPECT_NE(
-        string::npos,
-        interceptor->GetRequestBody(0).find(
-            "<app appid=\"abc\">"
-            "<event eventtype=\"3\" eventresult=\"1\" previousversion=\"1.0\" "
-            "nextversion=\"2.0\"/>"
-            "<event eventtype=\"14\" eventresult=\"0\" downloader=\"direct\" "
-            "errorcode=\"-1\" url=\"http://host1/path1\" downloaded=\"123\" "
-            "total=\"456\" download_time_ms=\"987\" previousversion=\"1.0\" "
-            "nextversion=\"2.0\"/>"
-            "<event eventtype=\"14\" eventresult=\"1\" downloader=\"bits\" "
-            "url=\"http://host2/path2\" downloaded=\"1230\" total=\"4560\" "
-            "download_time_ms=\"9870\" previousversion=\"1.0\" "
-            "nextversion=\"2.0\"/></app>"))
-        << interceptor->GetRequestsAsString();
+    const auto msg = interceptor->GetRequestBody(0);
+    constexpr char regex[] =
+        R"(<app appid="abc">)"
+        R"(<event eventtype="3" eventresult="1" )"
+        R"(previousversion="1\.0" nextversion="2\.0"/>)"
+        R"(<event eventtype="14" eventresult="0" downloader="direct" )"
+        R"(errorcode="-1" url="http://host1/path1" downloaded="123" )"
+        R"(total="456" download_time_ms="987" previousversion="1\.0" )"
+        R"(nextversion="2\.0"/>)"
+        R"(<event eventtype="14" eventresult="1" downloader="bits" )"
+        R"(url="http://host2/path2" downloaded="1230" total="4560" )"
+        R"(download_time_ms="9870" previousversion="1\.0" )"
+        R"(nextversion="2\.0"/></app>)";
+    EXPECT_TRUE(RE2::PartialMatch(msg, regex)) << msg;
+
     interceptor->Reset();
   }
 }
diff --git a/chromium/components/update_client/protocol_builder.cc b/chromium/components/update_client/protocol_builder.cc
index 54a172e1c50..0bcda6736ac 100644
--- a/chromium/components/update_client/protocol_builder.cc
+++ b/chromium/components/update_client/protocol_builder.cc
@@ -211,15 +211,18 @@ std::string BuildProtocolRequest(
     const std::string& os_long_name,
     const std::string& download_preference,
     const std::string& request_body,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     const std::unique_ptr<UpdaterState::Attributes>& updater_state_attributes) {
   std::string request = base::StringPrintf(
       "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
       "<request protocol=\"%s\" ",
       kProtocolVersion);
 
-  if (!additional_attributes.empty())
-    base::StringAppendF(&request, "%s ", additional_attributes.c_str());
+  if (!additional_attributes.empty()) {
+    for (const auto& attr : additional_attributes)
+      base::StringAppendF(&request, "%s=\"%s\" ", attr.first.c_str(),
+                          attr.second.c_str());
+  }
 
   // Constant information for this updater.
   base::StringAppendF(&request, "dedup=\"cr\" acceptformat=\"crx2,crx3\" ");
@@ -301,7 +304,7 @@ std::string BuildProtocolRequest(
   return request;
 }
 
-std::map<std::string, std::string> BuildUpdateCheckExtraRequestHeaders(
+base::flat_map<std::string, std::string> BuildUpdateCheckExtraRequestHeaders(
     scoped_refptr<Configurator> config,
     const std::vector<std::string>& ids,
     bool is_foreground) {
@@ -312,7 +315,7 @@ std::map<std::string, std::string> BuildUpdateCheckExtraRequestHeaders(
           ? ids
           : std::vector<std::string>(ids.cbegin(),
                                      ids.cbegin() + maxExtensionCount);
-  return std::map<std::string, std::string>{
+  return {
       {"X-Goog-Update-Updater",
        base::StringPrintf("%s-%s", config->GetProdId().c_str(),
                           config->GetBrowserVersion().GetString().c_str())},
@@ -327,7 +330,7 @@ std::string BuildUpdateCheckRequest(
     const std::vector<std::string>& ids_checked,
     const IdToComponentPtrMap& components,
     PersistedData* metadata,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     bool enabled_component_updates,
     const std::unique_ptr<UpdaterState::Attributes>& updater_state_attributes) {
   const std::string brand(SanitizeBrand(config.GetBrand()));
@@ -442,7 +445,7 @@ std::string BuildEventPingRequest(const Configurator& config,
                               config.GetBrowserVersion().GetString(),
                               config.GetChannel(), config.GetLang(),
                               config.GetOSLongName(),
-                              config.GetDownloadPreference(), app, "", nullptr);
+                              config.GetDownloadPreference(), app, {}, nullptr);
 }
 
 }  // namespace update_client
diff --git a/chromium/components/update_client/protocol_builder.h b/chromium/components/update_client/protocol_builder.h
index e323c82aad4..d00bf0c0fc9 100644
--- a/chromium/components/update_client/protocol_builder.h
+++ b/chromium/components/update_client/protocol_builder.h
@@ -10,6 +10,7 @@
 #include <string>
 #include <vector>
 
+#include "base/containers/flat_map.h"
 #include "components/update_client/component.h"
 #include "components/update_client/crx_downloader.h"
 #include "components/update_client/updater_state.h"
@@ -22,7 +23,7 @@ class PersistedData;
 // Creates the values for the DDOS extra request headers sent with the update
 // check. These headers include "X-Goog-Update-Updater",
 // "X-Goog-Update-AppId", and  "X-Goog-Update-Interactivity".
-std::map<std::string, std::string> BuildUpdateCheckExtraRequestHeaders(
+base::flat_map<std::string, std::string> BuildUpdateCheckExtraRequestHeaders(
     scoped_refptr<Configurator> config,
     const std::vector<std::string>& ids_checked,
     bool is_foreground);
@@ -48,7 +49,7 @@ std::string BuildUpdateCheckRequest(
     const std::vector<std::string>& ids_checked,
     const IdToComponentPtrMap& components,
     PersistedData* metadata,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     bool enabled_component_updates,
     const std::unique_ptr<UpdaterState::Attributes>& updater_state_attributes);
 
@@ -120,7 +121,7 @@ std::string BuildProtocolRequest(
     const std::string& os_long_name,
     const std::string& download_preference,
     const std::string& request_body,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     const std::unique_ptr<UpdaterState::Attributes>& updater_state_attributes);
 
 }  // namespace update_client
diff --git a/chromium/components/update_client/protocol_builder_unittest.cc b/chromium/components/update_client/protocol_builder_unittest.cc
index 0570e70e4f2..206959b2701 100644
--- a/chromium/components/update_client/protocol_builder_unittest.cc
+++ b/chromium/components/update_client/protocol_builder_unittest.cc
@@ -23,7 +23,7 @@ TEST(BuildProtocolRequest, SessionIdProdIdVersion) {
   // Verifies that |session_id|, |prod_id| and |version| are serialized.
   const string request = BuildProtocolRequest(
       "15160585-8ADE-4D3C-839B-1281A6035D1F", "some_prod_id", "1.0", "", "", "",
-      "", "", "", nullptr);
+      "", "", {}, nullptr);
   EXPECT_NE(
       string::npos,
       request.find(" sessionid=\"{15160585-8ADE-4D3C-839B-1281A6035D1F}\" "));
@@ -35,12 +35,12 @@ TEST(BuildProtocolRequest, SessionIdProdIdVersion) {
 TEST(BuildProtocolRequest, DownloadPreference) {
   // Verifies that an empty |download_preference| is not serialized.
   const string request_no_dlpref =
-      BuildProtocolRequest("1", "", "", "", "", "", "", "", "", nullptr);
+      BuildProtocolRequest("1", "", "", "", "", "", "", "", {}, nullptr);
   EXPECT_EQ(string::npos, request_no_dlpref.find(" dlpref="));
 
   // Verifies that |download_preference| is serialized.
   const string request_with_dlpref = BuildProtocolRequest(
-      "1", "", "", "", "", "", "some pref", "", "", nullptr);
+      "1", "", "", "", "", "", "some pref", "", {}, nullptr);
   EXPECT_NE(string::npos, request_with_dlpref.find(" dlpref=\"some pref\""));
 }
 
@@ -48,7 +48,7 @@ TEST(BuildProtocolRequest, UpdaterStateAttributes) {
   // When no updater state is provided, then check that the elements and
   // attributes related to the updater state are not serialized.
   std::string request =
-      BuildProtocolRequest("1", "", "", "", "", "", "", "", "", nullptr);
+      BuildProtocolRequest("1", "", "", "", "", "", "", "", {}, nullptr);
   EXPECT_EQ(std::string::npos, request.find(" domainjoined"));
   EXPECT_EQ(std::string::npos, request.find("<updater"));
 
@@ -62,7 +62,7 @@ TEST(BuildProtocolRequest, UpdaterStateAttributes) {
   attributes["autoupdatecheckenabled"] = "0";
   attributes["updatepolicy"] = "-1";
   request = BuildProtocolRequest(
-      "1", "", "", "", "", "", "", "", "",
+      "1", "", "", "", "", "", "", "", {},
       std::make_unique<UpdaterState::Attributes>(attributes));
   EXPECT_NE(std::string::npos, request.find(" domainjoined=\"1\""));
   const std::string updater_element =
diff --git a/chromium/components/update_client/request_sender.cc b/chromium/components/update_client/request_sender.cc
index be6e856db2b..b6657163b72 100644
--- a/chromium/components/update_client/request_sender.cc
+++ b/chromium/components/update_client/request_sender.cc
@@ -60,7 +60,7 @@ RequestSender::~RequestSender() {
 
 void RequestSender::Send(
     const std::vector<GURL>& urls,
-    const std::map<std::string, std::string>& request_extra_headers,
+    const base::flat_map<std::string, std::string>& request_extra_headers,
     const std::string& request_body,
     bool use_signing,
     RequestSenderCallback request_sender_callback) {
diff --git a/chromium/components/update_client/request_sender.h b/chromium/components/update_client/request_sender.h
index 10722312152..2ffdd62bd57 100644
--- a/chromium/components/update_client/request_sender.h
+++ b/chromium/components/update_client/request_sender.h
@@ -7,12 +7,12 @@
 
 #include <stdint.h>
 
-#include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
+#include "base/containers/flat_map.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread_checker.h"
@@ -54,11 +54,12 @@ class RequestSender {
   // If this optional parameter is set, the values of "fg" or "bg" are sent
   // for true or false values of this parameter. Otherwise the header is not
   // sent at all.
-  void Send(const std::vector<GURL>& urls,
-            const std::map<std::string, std::string>& request_extra_headers,
-            const std::string& request_body,
-            bool use_signing,
-            RequestSenderCallback request_sender_callback);
+  void Send(
+      const std::vector<GURL>& urls,
+      const base::flat_map<std::string, std::string>& request_extra_headers,
+      const std::string& request_body,
+      bool use_signing,
+      RequestSenderCallback request_sender_callback);
 
  private:
   // Combines the |url| and |query_params| parameters.
@@ -99,7 +100,7 @@ class RequestSender {
   const scoped_refptr<Configurator> config_;
 
   std::vector<GURL> urls_;
-  std::map<std::string, std::string> request_extra_headers_;
+  base::flat_map<std::string, std::string> request_extra_headers_;
   std::string request_body_;
   bool use_signing_;  // True if CUP signing is used.
   RequestSenderCallback request_sender_callback_;
diff --git a/chromium/components/update_client/request_sender_unittest.cc b/chromium/components/update_client/request_sender_unittest.cc
index e2eb26316d8..aa9e4c93c12 100644
--- a/chromium/components/update_client/request_sender_unittest.cc
+++ b/chromium/components/update_client/request_sender_unittest.cc
@@ -229,7 +229,7 @@ TEST_F(RequestSenderTest, RequestSendFailedNoUrls) {
   std::vector<GURL> urls;
   request_sender_ = std::make_unique<RequestSender>(config_);
   request_sender_->Send(
-      urls, std::map<std::string, std::string>(), "test", false,
+      urls, {}, "test", false,
       base::BindOnce(&RequestSenderTest::RequestSenderComplete,
                      base::Unretained(this)));
   RunThreads();
diff --git a/chromium/components/update_client/test_configurator.cc b/chromium/components/update_client/test_configurator.cc
index be07318b6fe..da9f2ddcc85 100644
--- a/chromium/components/update_client/test_configurator.cc
+++ b/chromium/components/update_client/test_configurator.cc
@@ -108,8 +108,9 @@ std::string TestConfigurator::GetOSLongName() const {
   return "Fake Operating System";
 }
 
-std::string TestConfigurator::ExtraRequestParams() const {
-  return "extra=\"foo\"";
+base::flat_map<std::string, std::string> TestConfigurator::ExtraRequestParams()
+    const {
+  return {{"extra", "foo"}};
 }
 
 std::string TestConfigurator::GetDownloadPreference() const {
diff --git a/chromium/components/update_client/test_configurator.h b/chromium/components/update_client/test_configurator.h
index 4868d734662..cf74358ac54 100644
--- a/chromium/components/update_client/test_configurator.h
+++ b/chromium/components/update_client/test_configurator.h
@@ -12,6 +12,7 @@
 #include <utility>
 #include <vector>
 
+#include "base/containers/flat_map.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "components/update_client/configurator.h"
@@ -84,7 +85,7 @@ class TestConfigurator : public Configurator {
   std::string GetBrand() const override;
   std::string GetLang() const override;
   std::string GetOSLongName() const override;
-  std::string ExtraRequestParams() const override;
+  base::flat_map<std::string, std::string> ExtraRequestParams() const override;
   std::string GetDownloadPreference() const override;
   scoped_refptr<network::SharedURLLoaderFactory> URLLoaderFactory()
       const override;
diff --git a/chromium/components/update_client/update_checker.cc b/chromium/components/update_client/update_checker.cc
index d915d3834d4..a2ce8f4ad6f 100644
--- a/chromium/components/update_client/update_checker.cc
+++ b/chromium/components/update_client/update_checker.cc
@@ -55,19 +55,21 @@ class UpdateCheckerImpl : public UpdateChecker {
   ~UpdateCheckerImpl() override;
 
   // Overrides for UpdateChecker.
-  void CheckForUpdates(const std::string& session_id,
-                       const std::vector<std::string>& ids_checked,
-                       const IdToComponentPtrMap& components,
-                       const std::string& additional_attributes,
-                       bool enabled_component_updates,
-                       UpdateCheckCallback update_check_callback) override;
+  void CheckForUpdates(
+      const std::string& session_id,
+      const std::vector<std::string>& ids_checked,
+      const IdToComponentPtrMap& components,
+      const base::flat_map<std::string, std::string>& additional_attributes,
+      bool enabled_component_updates,
+      UpdateCheckCallback update_check_callback) override;
 
  private:
   void ReadUpdaterStateAttributes();
-  void CheckForUpdatesHelper(const std::string& session_id,
-                             const IdToComponentPtrMap& components,
-                             const std::string& additional_attributes,
-                             bool enabled_component_updates);
+  void CheckForUpdatesHelper(
+      const std::string& session_id,
+      const IdToComponentPtrMap& components,
+      const base::flat_map<std::string, std::string>& additional_attributes,
+      bool enabled_component_updates);
   void OnRequestSenderComplete(int error,
                                const std::string& response,
                                int retry_after_sec);
@@ -101,7 +103,7 @@ void UpdateCheckerImpl::CheckForUpdates(
     const std::string& session_id,
     const std::vector<std::string>& ids_checked,
     const IdToComponentPtrMap& components,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     bool enabled_component_updates,
     UpdateCheckCallback update_check_callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ -136,7 +138,7 @@ void UpdateCheckerImpl::ReadUpdaterStateAttributes() {
 void UpdateCheckerImpl::CheckForUpdatesHelper(
     const std::string& session_id,
     const IdToComponentPtrMap& components,
-    const std::string& additional_attributes,
+    const base::flat_map<std::string, std::string>& additional_attributes,
     bool enabled_component_updates) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
diff --git a/chromium/components/update_client/update_checker.h b/chromium/components/update_client/update_checker.h
index 241e3a0a73c..d5126e193d5 100644
--- a/chromium/components/update_client/update_checker.h
+++ b/chromium/components/update_client/update_checker.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/callback.h"
+#include "base/containers/flat_map.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/optional.h"
@@ -38,18 +39,17 @@ class UpdateChecker {
 
   // Initiates an update check for the components specified by their ids.
   // |additional_attributes| provides a way to customize the <request> element.
-  // This value is inserted as-is, therefore it must be well-formed as an
-  // XML attribute string.
   // |is_foreground| controls the value of "X-Goog-Update-Interactivity"
   // header which is sent with the update check.
   // On completion, the state of |components| is mutated as required by the
   // server response received.
-  virtual void CheckForUpdates(const std::string& session_id,
-                               const std::vector<std::string>& ids_to_check,
-                               const IdToComponentPtrMap& components,
-                               const std::string& additional_attributes,
-                               bool enabled_component_updates,
-                               UpdateCheckCallback update_check_callback) = 0;
+  virtual void CheckForUpdates(
+      const std::string& session_id,
+      const std::vector<std::string>& ids_to_check,
+      const IdToComponentPtrMap& components,
+      const base::flat_map<std::string, std::string>& additional_attributes,
+      bool enabled_component_updates,
+      UpdateCheckCallback update_check_callback) = 0;
 
   static std::unique_ptr<UpdateChecker> Create(
       scoped_refptr<Configurator> config,
diff --git a/chromium/components/update_client/update_checker_unittest.cc b/chromium/components/update_client/update_checker_unittest.cc
index 8fc15dce703..266cfad3768 100644
--- a/chromium/components/update_client/update_checker_unittest.cc
+++ b/chromium/components/update_client/update_checker_unittest.cc
@@ -258,7 +258,7 @@ TEST_P(UpdateCheckerTest, UpdateCheckSuccess) {
 
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}, {"testrequest", "1"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -271,7 +271,8 @@ TEST_P(UpdateCheckerTest, UpdateCheckSuccess) {
   // Sanity check the request.
   const auto& request = post_interceptor_->GetRequestBody(0);
   EXPECT_THAT(request,
-              testing::HasSubstr(R"(request protocol="3.1" extra="params")"));
+              testing::HasSubstr(
+                  R"(request protocol="3.1" extra="params" testrequest="1")"));
   // The request must not contain any "dlpref" in the default case.
   EXPECT_THAT(request, testing::Not(testing::HasSubstr(R"( dlpref=")")));
   EXPECT_THAT(request,
@@ -347,7 +348,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckInvalidAp) {
   component->crx_component_->installer_attributes["ap"] = std::string(257, 'a');
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
 
@@ -375,7 +376,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckSuccessNoBrand) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
 
@@ -403,7 +404,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckError) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -432,7 +433,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckDownloadPreference) {
 
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -457,7 +458,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckCupError) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
 
@@ -498,7 +499,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckRequiresEncryptionError) {
   component->crx_component_->requires_network_encryption = true;
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -527,7 +528,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckLastRollCall) {
   activity_data_service_->SetDaysSinceLastRollCall(kUpdateItemId, 5);
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -535,7 +536,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckLastRollCall) {
   update_checker_ = UpdateChecker::Create(config_, metadata_.get());
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -570,7 +571,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckLastActive) {
   activity_data_service_->SetDaysSinceLastActive(kUpdateItemId, 10);
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -582,7 +583,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckLastActive) {
   update_checker_ = UpdateChecker::Create(config_, metadata_.get());
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -593,7 +594,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckLastActive) {
   update_checker_ = UpdateChecker::Create(config_, metadata_.get());
   update_checker_->CheckForUpdates(
       update_context_->session_id, {kUpdateItemId}, components,
-      "extra=\"params\"", true,
+      {{"extra", "params"}}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -626,7 +627,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckInstallSource) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -639,7 +640,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckInstallSource) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -656,7 +657,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckInstallSource) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -673,7 +674,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckInstallSource) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -696,7 +697,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -712,7 +713,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -727,7 +728,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -743,7 +744,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -759,7 +760,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -777,7 +778,7 @@ TEST_F(UpdateCheckerTest, ComponentDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -811,7 +812,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckUpdateDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -831,7 +832,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckUpdateDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", false,
+      update_context_->session_id, {kUpdateItemId}, components, {}, false,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -852,7 +853,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckUpdateDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -872,7 +873,7 @@ TEST_F(UpdateCheckerTest, UpdateCheckUpdateDisabled) {
       std::make_unique<PartialMatch>("updatecheck"),
       test_file("updatecheck_reply_1.xml")));
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -893,7 +894,7 @@ TEST_F(UpdateCheckerTest, NoUpdateActionRun) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -930,7 +931,7 @@ TEST_F(UpdateCheckerTest, UpdatePauseResume) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -964,7 +965,7 @@ TEST_F(UpdateCheckerTest, UpdateResetUpdateChecker) {
 
   update_checker_ = UpdateChecker::Create(config_, metadata_.get());
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   runloop.Run();
@@ -983,7 +984,7 @@ TEST_F(UpdateCheckerTest, ParseErrorProtocolVersionMismatch) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
@@ -1012,7 +1013,7 @@ TEST_F(UpdateCheckerTest, ParseErrorAppStatusErrorUnknownApplication) {
   components[kUpdateItemId] = MakeComponent();
 
   update_checker_->CheckForUpdates(
-      update_context_->session_id, {kUpdateItemId}, components, "", true,
+      update_context_->session_id, {kUpdateItemId}, components, {}, true,
       base::BindOnce(&UpdateCheckerTest::UpdateCheckComplete,
                      base::Unretained(this)));
   RunThreads();
diff --git a/chromium/components/update_client/update_client_unittest.cc b/chromium/components/update_client/update_client_unittest.cc
index dc41bbd13b6..8f1da0f0367 100644
--- a/chromium/components/update_client/update_client_unittest.cc
+++ b/chromium/components/update_client/update_client_unittest.cc
@@ -6,6 +6,7 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/containers/flat_map.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
@@ -245,12 +246,13 @@ TEST_F(UpdateClientTest, OneCrxNoUpdate) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
       EXPECT_TRUE(enabled_component_updates);
       EXPECT_EQ(1u, ids_to_check.size());
@@ -363,12 +365,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateNoUpdate) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -579,12 +582,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateFirstServerIgnoresSecond) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -786,12 +790,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateNoCrxComponentData) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -974,12 +979,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateNoCrxComponentDataAtAll) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       NOTREACHED();
     }
   };
@@ -1080,12 +1086,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateDownloadTimeout) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -1354,12 +1361,13 @@ TEST_F(UpdateClientTest, OneCrxDiffUpdate) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
 
       static int num_call = 0;
@@ -1682,12 +1690,13 @@ TEST_F(UpdateClientTest, OneCrxInstallError) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -1873,12 +1882,13 @@ TEST_F(UpdateClientTest, OneCrxDiffUpdateFailsFullUpdateSucceeds) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
 
       static int num_call = 0;
@@ -2173,12 +2183,13 @@ TEST_F(UpdateClientTest, OneCrxNoUpdateQueuedCall) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
       EXPECT_TRUE(enabled_component_updates);
       EXPECT_EQ(1u, ids_to_check.size());
@@ -2288,12 +2299,13 @@ TEST_F(UpdateClientTest, OneCrxInstall) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -2466,12 +2478,13 @@ TEST_F(UpdateClientTest, OneCrxInstallNoCrxComponentData) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       NOTREACHED();
     }
   };
@@ -2580,12 +2593,13 @@ TEST_F(UpdateClientTest, ConcurrentInstallSameCRX) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
       EXPECT_TRUE(enabled_component_updates);
       EXPECT_EQ(1u, ids_to_check.size());
@@ -2689,12 +2703,13 @@ TEST_F(UpdateClientTest, EmptyIdList) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       NOTREACHED();
     }
   };
@@ -2750,12 +2765,13 @@ TEST_F(UpdateClientTest, SendUninstallPing) {
       return nullptr;
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       NOTREACHED();
     }
   };
@@ -2854,12 +2870,13 @@ TEST_F(UpdateClientTest, RetryAfter) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
 
       static int num_call = 0;
@@ -3036,12 +3053,13 @@ TEST_F(UpdateClientTest, TwoCrxUpdateOneUpdateDisabled) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -3282,12 +3300,13 @@ TEST_F(UpdateClientTest, OneCrxUpdateCheckFails) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
       EXPECT_TRUE(enabled_component_updates);
       EXPECT_EQ(1u, ids_to_check.size());
@@ -3422,12 +3441,13 @@ TEST_F(UpdateClientTest, OneCrxErrorUnknownApp) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       EXPECT_FALSE(session_id.empty());
       EXPECT_TRUE(enabled_component_updates);
       EXPECT_EQ(4u, ids_to_check.size());
@@ -3579,12 +3599,13 @@ TEST_F(UpdateClientTest, ActionRun_Install) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
@@ -3743,12 +3764,13 @@ TEST_F(UpdateClientTest, ActionRun_NoUpdate) {
       return std::make_unique<MockUpdateChecker>();
     }
 
-    void CheckForUpdates(const std::string& session_id,
-                         const std::vector<std::string>& ids_to_check,
-                         const IdToComponentPtrMap& components,
-                         const std::string& additional_attributes,
-                         bool enabled_component_updates,
-                         UpdateCheckCallback update_check_callback) override {
+    void CheckForUpdates(
+        const std::string& session_id,
+        const std::vector<std::string>& ids_to_check,
+        const IdToComponentPtrMap& components,
+        const base::flat_map<std::string, std::string>& additional_attributes,
+        bool enabled_component_updates,
+        UpdateCheckCallback update_check_callback) override {
       /*
       Mock the following response:
 
diff --git a/chromium/components/update_client/utils.cc b/chromium/components/update_client/utils.cc
index 131288f3ce7..fc2e42bd6e0 100644
--- a/chromium/components/update_client/utils.cc
+++ b/chromium/components/update_client/utils.cc
@@ -9,7 +9,6 @@
 #include <algorithm>
 #include <cmath>
 #include <cstring>
-#include <map>
 #include <vector>
 
 #include "base/callback.h"
@@ -40,7 +39,8 @@ namespace update_client {
 
 std::unique_ptr<network::SimpleURLLoader> SendProtocolRequest(
     const GURL& url,
-    const std::map<std::string, std::string>& protocol_request_extra_headers,
+    const base::flat_map<std::string, std::string>&
+        protocol_request_extra_headers,
     const std::string& protocol_request,
     network::SimpleURLLoader::BodyAsStringCallback callback,
     scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory) {
diff --git a/chromium/components/update_client/utils.h b/chromium/components/update_client/utils.h
index e8ec3b7247d..77fc76c178e 100644
--- a/chromium/components/update_client/utils.h
+++ b/chromium/components/update_client/utils.h
@@ -5,13 +5,13 @@
 #ifndef COMPONENTS_UPDATE_CLIENT_UTILS_H_
 #define COMPONENTS_UPDATE_CLIENT_UTILS_H_
 
-#include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/callback_forward.h"
+#include "base/containers/flat_map.h"
 #include "base/memory/ref_counted.h"
 #include "components/update_client/update_client.h"
 
@@ -45,7 +45,8 @@ using LoadCompleteCallback =
 // expected to contain XML data. The caller owns the returned object.
 std::unique_ptr<network::SimpleURLLoader> SendProtocolRequest(
     const GURL& url,
-    const std::map<std::string, std::string>& protocol_request_extra_headers,
+    const base::flat_map<std::string, std::string>&
+        protocol_request_extra_headers,
     const std::string& protocol_request,
     LoadCompleteCallback callback,
     scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory);