diff --git a/chrome/app/media_router_strings.grdp b/chrome/app/media_router_strings.grdp
index fd375e4..2eebf2e 100644
--- a/chrome/app/media_router_strings.grdp
+++ b/chrome/app/media_router_strings.grdp

@@ -185,7 +185,7 @@
     Always use mirroring
   </message>
   <message name="IDS_MEDIA_ROUTER_ROUTE_DETAILS_FULLSCREEN_VIDEOS_DROPDOWN_TITLE" desc="The title for a toggle setting to choose whether fullscreen videos should always be mirrored (played locally and remotely), or played only remotely.">
-    Show fullscreen videos on:
+    Show fullscreen videos on
   </message>
   <message name="IDS_MEDIA_ROUTER_ROUTE_DETAILS_FULLSCREEN_VIDEOS_BOTH_SCREENS" desc="Settings option to play fullscreen videos both locally and remotely.">
     Both screens

diff --git a/chrome/browser/android/chrome_feature_list.cc b/chrome/browser/android/chrome_feature_list.cc
index db61e06b..e70c6db 100644
--- a/chrome/browser/android/chrome_feature_list.cc
+++ b/chrome/browser/android/chrome_feature_list.cc

@@ -224,7 +224,7 @@
                                         base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kChromeSmartSelection{"ChromeSmartSelection",
-                                          base::FEATURE_DISABLED_BY_DEFAULT};
+                                          base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kContentSuggestionsScrollToLoad{
     "ContentSuggestionsScrollToLoad", base::FEATURE_ENABLED_BY_DEFAULT};

diff --git a/chrome/browser/chromeos/accessibility/accessibility_manager_browsertest.cc b/chrome/browser/chromeos/accessibility/accessibility_manager_browsertest.cc
index a7369eb..463135f 100644
--- a/chrome/browser/chromeos/accessibility/accessibility_manager_browsertest.cc
+++ b/chrome/browser/chromeos/accessibility/accessibility_manager_browsertest.cc

@@ -51,13 +51,14 @@
 
 namespace {
 
-const char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserGaiaId[] = "9876543210";
 
-const int kTestAutoclickDelayMs = 2000;
+constexpr int kTestAutoclickDelayMs = 2000;
 
 // Test user name for supervised user. The domain part must be matched with
 // user_manager::kSupervisedUserDomain.
-const char kTestSupervisedUserName[] = "test@locally-managed.localhost";
+constexpr char kTestSupervisedUserName[] = "test@locally-managed.localhost";
 
 class MockAccessibilityObserver {
  public:
@@ -303,7 +304,8 @@
 
   MockBrailleController braille_controller_;
 
-  const AccountId test_account_id_ = AccountId::FromUserEmail(kTestUserName);
+  const AccountId test_account_id_ =
+      AccountId::FromUserEmailGaiaId(kTestUserName, kTestUserGaiaId);
 
   DISALLOW_COPY_AND_ASSIGN(AccessibilityManagerTest);
 };
@@ -640,7 +642,7 @@
 
 class AccessibilityManagerUserTypeTest
     : public AccessibilityManagerTest,
-      public ::testing::WithParamInterface<const char*> {
+      public ::testing::WithParamInterface<AccountId> {
  protected:
   AccessibilityManagerUserTypeTest() {}
   virtual ~AccessibilityManagerUserTypeTest() {}
@@ -652,9 +654,10 @@
 INSTANTIATE_TEST_CASE_P(
     UserTypeInstantiation,
     AccessibilityManagerUserTypeTest,
-    ::testing::Values(kTestUserName,
-                      user_manager::GuestAccountId().GetUserEmail().c_str(),
-                      kTestSupervisedUserName));
+    ::testing::Values(AccountId::FromUserEmailGaiaId(kTestUserName,
+                                                     kTestUserGaiaId),
+                      user_manager::GuestAccountId(),
+                      AccountId::FromUserEmail(kTestSupervisedUserName)));
 
 IN_PROC_BROWSER_TEST_P(AccessibilityManagerUserTypeTest,
                        EnableOnLoginScreenAndLogin) {
@@ -678,7 +681,7 @@
   EXPECT_TRUE(IsMonoAudioEnabled());
 
   // Logs in.
-  const AccountId account_id = AccountId::FromUserEmail(GetParam());
+  const AccountId account_id = GetParam();
   auto* session_manager = session_manager::SessionManager::Get();
   session_manager->CreateSession(account_id, account_id.GetUserEmail());
 
@@ -711,7 +714,7 @@
 
 IN_PROC_BROWSER_TEST_P(AccessibilityManagerUserTypeTest, BrailleWhenLoggedIn) {
   // Logs in.
-  const AccountId account_id = AccountId::FromUserEmail(GetParam());
+  const AccountId account_id = GetParam();
   auto* session_manager = session_manager::SessionManager::Get();
   session_manager->CreateSession(account_id, account_id.GetUserEmail());
   StartUserSession(account_id);

diff --git a/chrome/browser/chromeos/accessibility/magnification_manager_browsertest.cc b/chrome/browser/chromeos/accessibility/magnification_manager_browsertest.cc
index db13911..b42bbfa 100644
--- a/chrome/browser/chromeos/accessibility/magnification_manager_browsertest.cc
+++ b/chrome/browser/chromeos/accessibility/magnification_manager_browsertest.cc

@@ -32,7 +32,8 @@
 
 namespace {
 
-const char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserGaiaId[] = "9876543210";
 
 void SetMagnifierEnabled(bool enabled) {
   MagnificationManager::Get()->SetMagnifierEnabled(enabled);
@@ -158,7 +159,8 @@
         ProfileManager::GetActiveUserProfile());
   }
 
-  const AccountId test_account_id_ = AccountId::FromUserEmail(kTestUserName);
+  const AccountId test_account_id_ =
+      AccountId::FromUserEmailGaiaId(kTestUserName, kTestUserGaiaId);
 
   DISALLOW_COPY_AND_ASSIGN(MagnificationManagerTest);
 };

diff --git a/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api_unittest.cc b/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api_unittest.cc
index 82fce006..75ded6b 100644
--- a/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api_unittest.cc
+++ b/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api_unittest.cc

@@ -34,10 +34,11 @@
 namespace chromeos {
 namespace {
 
-const char* kTestUserEmail = "testuser@gmail.com";
-const char* kTestUserEmailHash = "testuser@gmail.com-hash";
-const char* kValidPassword = "valid";
-const char* kInvalidPassword = "invalid";
+constexpr char kTestUserEmail[] = "testuser@gmail.com";
+constexpr char kTestUserGaiaId[] = "9876543210";
+constexpr char kTestUserEmailHash[] = "testuser@gmail.com-hash";
+constexpr char kValidPassword[] = "valid";
+constexpr char kInvalidPassword[] = "invalid";
 
 class FakeEasyUnlockService : public EasyUnlockServiceRegular {
  public:
@@ -70,7 +71,8 @@
 
 ExtendedAuthenticator* CreateFakeAuthenticator(
     AuthStatusConsumer* auth_status_consumer) {
-  AccountId account_id = AccountId::FromUserEmail(kTestUserEmail);
+  const AccountId account_id =
+      AccountId::FromUserEmailGaiaId(kTestUserEmail, kTestUserGaiaId);
   UserContext expected_context(account_id);
   expected_context.SetKey(Key(kValidPassword));
 
@@ -109,7 +111,8 @@
     quick_unlock::EnableForTesting(quick_unlock::PinStorageType::kPrefs);
 
     // Setup a primary user.
-    auto test_account = AccountId::FromUserEmail(kTestUserEmail);
+    auto test_account =
+        AccountId::FromUserEmailGaiaId(kTestUserEmail, kTestUserGaiaId);
     fake_user_manager_->AddUser(test_account);
     fake_user_manager_->UserLoggedIn(test_account, kTestUserEmailHash, false);
 

diff --git a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
index 941db1b..61bd09f6 100644
--- a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
+++ b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc

@@ -68,16 +68,17 @@
 // NOTE: Root dir for drive file system is set by Chrome's drive implementation,
 // but the test will have to make sure the mount point is added before
 // starting a test extension using WaitUntilDriveMountPointIsAdded().
-const char kLocalMountPointName[] = "local";
-const char kRestrictedMountPointName[] = "restricted";
+constexpr char kLocalMountPointName[] = "local";
+constexpr char kRestrictedMountPointName[] = "restricted";
 
 // Default file content for the test files.
-const char kTestFileContent[] = "This is some test content.";
+constexpr char kTestFileContent[] = "This is some test content.";
 
 // User account email and directory hash for secondary account for multi-profile
 // sensitive test cases.
-const char kSecondProfileAccount[] = "profile2@test.com";
-const char kSecondProfileHash[] = "fileBrowserApiTestProfile2";
+constexpr char kSecondProfileAccount[] = "profile2@test.com";
+constexpr char kSecondProfileGiaId[] = "9876543210";
+constexpr char kSecondProfileHash[] = "fileBrowserApiTestProfile2";
 
 class FakeSelectFileDialog : public ui::SelectFileDialog {
  public:
@@ -503,7 +504,9 @@
     base::FilePath user_data_directory;
     PathService::Get(chrome::DIR_USER_DATA, &user_data_directory);
     session_manager::SessionManager::Get()->CreateSession(
-        AccountId::FromUserEmail(kSecondProfileAccount), kSecondProfileHash);
+        AccountId::FromUserEmailGaiaId(kSecondProfileAccount,
+                                       kSecondProfileGiaId),
+        kSecondProfileHash);
     // Set up the secondary profile.
     base::FilePath profile_dir =
         user_data_directory.Append(

diff --git a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
index d1ef79a..0e60ec2 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc

@@ -627,7 +627,8 @@
   // Adds a new user for testing to the current session.
   void AddUser(const TestAccountInfo& info, bool log_in) {
     base::ScopedAllowBlockingForTesting allow_blocking;
-    const AccountId account_id(AccountId::FromUserEmail(info.email));
+    const AccountId account_id(
+        AccountId::FromUserEmailGaiaId(info.email, info.gaia_id));
     if (log_in) {
       session_manager::SessionManager::Get()->CreateSession(account_id,
                                                             info.hash);

diff --git a/chrome/browser/chromeos/login/login_browsertest.cc b/chrome/browser/chromeos/login/login_browsertest.cc
index 088c591..830ac748 100644
--- a/chrome/browser/chromeos/login/login_browsertest.cc
+++ b/chrome/browser/chromeos/login/login_browsertest.cc

@@ -266,7 +266,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(LoginTest, PRE_GaiaAuthOffline) {
-  RegisterUser(kTestUser);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser, kGaiaId));
   StartupUtils::MarkOobeCompleted();
   CrosSettings::Get()->SetBoolean(kAccountsPrefShowUserNamesOnSignIn, false);
 }

diff --git a/chrome/browser/chromeos/login/login_manager_test.cc b/chrome/browser/chromeos/login/login_manager_test.cc
index aa162a96..330e36b8 100644
--- a/chrome/browser/chromeos/login/login_manager_test.cc
+++ b/chrome/browser/chromeos/login/login_manager_test.cc

@@ -25,6 +25,8 @@
 #include "chromeos/login/auth/key.h"
 #include "chromeos/login/auth/user_context.h"
 #include "components/prefs/scoped_user_pref_update.h"
+#include "components/signin/core/account_id/account_id.h"
+#include "components/user_manager/known_user.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_service.h"
@@ -43,19 +45,18 @@
 
 namespace {
 
-const char kGAIAHost[] = "accounts.google.com";
-const char kTestUserinfoToken1[] = "fake-userinfo-token-1";
-const char kTestRefreshToken1[] = "fake-refresh-token-1";
-const char kTestUserinfoToken2[] = "fake-userinfo-token-2";
-const char kTestRefreshToken2[] = "fake-refresh-token-2";
+constexpr char kGAIAHost[] = "accounts.google.com";
+constexpr char kTestUserinfoToken1[] = "fake-userinfo-token-1";
+constexpr char kTestRefreshToken1[] = "fake-refresh-token-1";
+constexpr char kTestUserinfoToken2[] = "fake-userinfo-token-2";
+constexpr char kTestRefreshToken2[] = "fake-refresh-token-2";
 
-UserContext CreateUserContext(const std::string& user_id) {
-  UserContext user_context(AccountId::FromUserEmailGaiaId(
-      user_id, LoginManagerTest::GetGaiaIDForUserID(user_id)));
+UserContext CreateUserContext(const AccountId& account_id) {
+  UserContext user_context(account_id);
   user_context.SetKey(Key("password"));
-  if (user_id == LoginManagerTest::kEnterpriseUser1) {
+  if (account_id.GetUserEmail() == LoginManagerTest::kEnterpriseUser1) {
     user_context.SetRefreshToken(kTestRefreshToken1);
-  } else if (user_id == LoginManagerTest::kEnterpriseUser2) {
+  } else if (account_id.GetUserEmail() == LoginManagerTest::kEnterpriseUser2) {
     user_context.SetRefreshToken(kTestRefreshToken2);
   }
   return user_context;
@@ -63,8 +64,10 @@
 
 }  // namespace
 
-const char LoginManagerTest::kEnterpriseUser1[] = "user-1@example.com";
-const char LoginManagerTest::kEnterpriseUser2[] = "user-2@example.com";
+constexpr char LoginManagerTest::kEnterpriseUser1[] = "user-1@example.com";
+constexpr char LoginManagerTest::kEnterpriseUser1GaiaId[] = "0000111111";
+constexpr char LoginManagerTest::kEnterpriseUser2[] = "user-2@example.com";
+constexpr char LoginManagerTest::kEnterpriseUser2GaiaId[] = "0000222222";
 
 LoginManagerTest::LoginManagerTest(bool should_launch_browser)
     : should_launch_browser_(should_launch_browser), web_contents_(NULL) {
@@ -151,9 +154,12 @@
   MixinBasedBrowserTest::SetUpOnMainThread();
 }
 
-void LoginManagerTest::RegisterUser(const std::string& user_id) {
+void LoginManagerTest::RegisterUser(const AccountId& account_id) {
   ListPrefUpdate users_pref(g_browser_process->local_state(), "LoggedInUsers");
-  users_pref->AppendIfNotPresent(base::MakeUnique<base::Value>(user_id));
+  users_pref->AppendIfNotPresent(
+      std::make_unique<base::Value>(account_id.GetUserEmail()));
+  if (user_manager::UserManager::IsInitialized())
+    user_manager::known_user::SetProfileEverInitialized(account_id, false);
 }
 
 void LoginManagerTest::SetExpectedCredentials(const UserContext& user_context) {
@@ -193,20 +199,24 @@
   return false;
 }
 
-void LoginManagerTest::LoginUser(const std::string& user_id) {
-  const UserContext user_context = CreateUserContext(user_id);
+void LoginManagerTest::LoginUser(const AccountId& account_id) {
+  const UserContext user_context = CreateUserContext(account_id);
   SetExpectedCredentials(user_context);
   EXPECT_TRUE(TryToLogin(user_context));
 }
 
-void LoginManagerTest::AddUser(const std::string& user_id) {
-  const UserContext user_context = CreateUserContext(user_id);
+void LoginManagerTest::AddUser(const AccountId& account_id) {
+  const UserContext user_context = CreateUserContext(account_id);
   SetExpectedCredentials(user_context);
   EXPECT_TRUE(AddUserToSession(user_context));
 }
 
 // static
 std::string LoginManagerTest::GetGaiaIDForUserID(const std::string& user_id) {
+  if (user_id == LoginManagerTest::kEnterpriseUser1)
+    return LoginManagerTest::kEnterpriseUser1GaiaId;
+  if (user_id == LoginManagerTest::kEnterpriseUser2)
+    return LoginManagerTest::kEnterpriseUser2GaiaId;
   return "gaia-id-" + user_id;
 }
 

diff --git a/chrome/browser/chromeos/login/login_manager_test.h b/chrome/browser/chromeos/login/login_manager_test.h
index 027e3c0..7476b2159 100644
--- a/chrome/browser/chromeos/login/login_manager_test.h
+++ b/chrome/browser/chromeos/login/login_manager_test.h

@@ -13,6 +13,8 @@
 #include "chrome/browser/chromeos/login/test/js_checker.h"
 #include "google_apis/gaia/fake_gaia.h"
 
+class AccountId;
+
 namespace content {
 class WebContents;
 }  // namespace content
@@ -41,7 +43,7 @@
   // Registers the user with the given |user_id| on the device.
   // This method should be called in PRE_* test.
   // TODO(dzhioev): Add the ability to register users without a PRE_* test.
-  void RegisterUser(const std::string& user_id);
+  void RegisterUser(const AccountId& account_id);
 
   // Set expected credentials for next login attempt.
   void SetExpectedCredentials(const UserContext& user_context);
@@ -57,10 +59,10 @@
   bool AddUserToSession(const UserContext& user_context);
 
   // Log in user with |user_id|. User should be registered using RegisterUser().
-  void LoginUser(const std::string& user_id);
+  void LoginUser(const AccountId& account_id);
 
   // Add user with |user_id| to session.
-  void AddUser(const std::string& user_id);
+  void AddUser(const AccountId& user_id);
 
   // Executes given JS |expression| in |web_contents_| and checks
   // that it is true.
@@ -81,7 +83,9 @@
   // For your convenience, the e-mail addresses for users that have been set up
   // in this way are provided below.
   static const char kEnterpriseUser1[];
+  static const char kEnterpriseUser1GaiaId[];
   static const char kEnterpriseUser2[];
+  static const char kEnterpriseUser2GaiaId[];
 
  protected:
   FakeGaia fake_gaia_;

diff --git a/chrome/browser/chromeos/login/login_ui_browsertest.cc b/chrome/browser/chromeos/login/login_ui_browsertest.cc
index b1090a0..c16ac29d 100644
--- a/chrome/browser/chromeos/login/login_ui_browsertest.cc
+++ b/chrome/browser/chromeos/login/login_ui_browsertest.cc

@@ -25,14 +25,22 @@
 
 namespace {
 
-const char kTestUser1[] = "test-user1@gmail.com";
-const char kTestUser2[] = "test-user2@gmail.com";
+struct {
+  const char* email;
+  const char* gaia_id;
+} const kTestUsers[] = {{"test-user1@gmail.com", "1111111111"},
+                        {"test-user2@gmail.com", "2222222222"}};
 
 }  // namespace
 
 class LoginUITest : public chromeos::LoginManagerTest {
  public:
   LoginUITest() : LoginManagerTest(false) {
+    for (size_t i = 0; i < arraysize(kTestUsers); ++i) {
+      test_users_.emplace_back(AccountId::FromUserEmailGaiaId(
+          kTestUsers[i].email, kTestUsers[i].gaia_id));
+    }
+
     screenshot_testing_ = new ScreenshotTestingMixin;
     screenshot_testing_->IgnoreArea(areas::kClockArea);
     screenshot_testing_->IgnoreArea(areas::kFirstUserpod);
@@ -42,12 +50,14 @@
   ~LoginUITest() override {}
 
  protected:
+  std::vector<AccountId> test_users_;
+
   ScreenshotTestingMixin* screenshot_testing_;
 };
 
 IN_PROC_BROWSER_TEST_F(LoginUITest, PRE_LoginUIVisible) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   StartupUtils::MarkOobeCompleted();
 }
 
@@ -58,10 +68,14 @@
   JSExpect(
       "document.querySelectorAll('.pod:not(#user-pod-template)').length == 2");
 
-  JSExpect("document.querySelectorAll('.pod:not(#user-pod-template)')[0]"
-           ".user.emailAddress == '" + std::string(kTestUser1) + "'");
-  JSExpect("document.querySelectorAll('.pod:not(#user-pod-template)')[1]"
-           ".user.emailAddress == '" + std::string(kTestUser2) + "'");
+  JSExpect(
+      "document.querySelectorAll('.pod:not(#user-pod-template)')[0]"
+      ".user.emailAddress == '" +
+      test_users_[0].GetUserEmail() + "'");
+  JSExpect(
+      "document.querySelectorAll('.pod:not(#user-pod-template)')[1]"
+      ".user.emailAddress == '" +
+      test_users_[1].GetUserEmail() + "'");
   screenshot_testing_->RunScreenshotTesting("LoginUITest-LoginUIVisible");
 }
 
@@ -83,8 +97,8 @@
 }
 
 IN_PROC_BROWSER_TEST_F(LoginUITest, PRE_LoginNoExceptions) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   StartupUtils::MarkOobeCompleted();
 }
 

diff --git a/chrome/browser/chromeos/login/login_ui_keyboard_browsertest.cc b/chrome/browser/chromeos/login/login_ui_keyboard_browsertest.cc
index 046c73a..ef826887 100644
--- a/chrome/browser/chromeos/login/login_ui_keyboard_browsertest.cc
+++ b/chrome/browser/chromeos/login/login_ui_keyboard_browsertest.cc

@@ -24,9 +24,12 @@
 
 namespace {
 
-const char kTestUser1[] = "test-user1@gmail.com";
-const char kTestUser2[] = "test-user2@gmail.com";
-const char kTestUser3[] = "test-user3@gmail.com";
+constexpr char kTestUser1[] = "test-user1@gmail.com";
+constexpr char kTestUser1GaiaId[] = "1111111111";
+constexpr char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser2GaiaId[] = "2222222222";
+constexpr char kTestUser3[] = "test-user3@gmail.com";
+constexpr char kTestUser3GaiaId[] = "3333333333";
 
 void Append_en_US_InputMethods(std::vector<std::string>* out) {
   out->push_back("xkb:us::eng");
@@ -117,8 +120,8 @@
 };
 
 IN_PROC_BROWSER_TEST_F(LoginUIKeyboardTest, PRE_CheckPODScreenDefault) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
 
   StartupUtils::MarkOobeCompleted();
 }
@@ -137,8 +140,8 @@
 }
 
 IN_PROC_BROWSER_TEST_F(LoginUIKeyboardTest, PRE_CheckPODScreenWithUsers) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
 
   InitUserLastInputMethod();
 
@@ -234,9 +237,9 @@
 
 IN_PROC_BROWSER_TEST_F(LoginUIKeyboardTestWithUsersAndOwner,
                        PRE_CheckPODScreenKeyboard) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
-  RegisterUser(kTestUser3);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser3, kTestUser3GaiaId));
 
   InitUserLastInputMethod();
 

diff --git a/chrome/browser/chromeos/login/proxy_auth_dialog_browsertest.cc b/chrome/browser/chromeos/login/proxy_auth_dialog_browsertest.cc
index 4b70539..3c0fa46 100644
--- a/chrome/browser/chromeos/login/proxy_auth_dialog_browsertest.cc
+++ b/chrome/browser/chromeos/login/proxy_auth_dialog_browsertest.cc

@@ -86,7 +86,8 @@
 
 IN_PROC_BROWSER_TEST_F(ProxyAuthOnUserBoardScreenTest,
                        PRE_ProxyAuthDialogOnUserBoardScreen) {
-  RegisterUser("test-user@gmail.com");
+  RegisterUser(
+      AccountId::FromUserEmailGaiaId("test-user@gmail.com", "1234567890"));
   StartupUtils::MarkOobeCompleted();
 }
 

diff --git a/chrome/browser/chromeos/login/reset_browsertest.cc b/chrome/browser/chromeos/login/reset_browsertest.cc
index 33a1541..307fa76 100644
--- a/chrome/browser/chromeos/login/reset_browsertest.cc
+++ b/chrome/browser/chromeos/login/reset_browsertest.cc

@@ -26,7 +26,8 @@
 
 namespace {
 
-const char kTestUser1[] = "test-user1@gmail.com";
+constexpr char kTestUser1[] = "test-user1@gmail.com";
+constexpr char kTestUser1GaiaId[] = "test-user1@gmail.com";
 
 }  // namespace
 
@@ -61,7 +62,7 @@
   }
 
   void RegisterSomeUser() {
-    RegisterUser(kTestUser1);
+    RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
     StartupUtils::MarkOobeCompleted();
   }
 

diff --git a/chrome/browser/chromeos/login/screens/user_selection_screen_browsertest.cc b/chrome/browser/chromeos/login/screens/user_selection_screen_browsertest.cc
index 685f0b6..765d49b 100644
--- a/chrome/browser/chromeos/login/screens/user_selection_screen_browsertest.cc
+++ b/chrome/browser/chromeos/login/screens/user_selection_screen_browsertest.cc

@@ -25,11 +25,16 @@
 // Consumer user according to BrowserPolicyConnector::IsNonEnterpriseUser
 // (@gmail.com).
 constexpr char kTestUser1[] = "test-user1@gmail.com";
+constexpr char kTestUser1GaiaId[] = "1111111111";
+
 // Consumer user according to BrowserPolicyConnector::IsNonEnterpriseUser
 // (@gmail.com).
 constexpr char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser2GaiaId[] = "2222222222";
+
 // No consumer user according to BrowserPolicyConnector::IsNonEnterpriseUser.
 constexpr char kManagedTestUser[] = "manager@example.com";
+constexpr char kManagedTestUserGaiaId[] = "3333333333";
 
 }  // namespace
 
@@ -73,9 +78,10 @@
 
 IN_PROC_BROWSER_TEST_F(UserSelectionScreenTest,
                        PRE_ShowDircryptoMigrationBanner) {
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
-  RegisterUser(kManagedTestUser);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
+  RegisterUser(
+      AccountId::FromUserEmailGaiaId(kManagedTestUser, kManagedTestUserGaiaId));
   StartupUtils::MarkOobeCompleted();
 }
 

diff --git a/chrome/browser/chromeos/login/session/chrome_session_manager_browsertest.cc b/chrome/browser/chromeos/login/session/chrome_session_manager_browsertest.cc
index 11f060ec..cc46db0 100644
--- a/chrome/browser/chromeos/login/session/chrome_session_manager_browsertest.cc
+++ b/chrome/browser/chromeos/login/session/chrome_session_manager_browsertest.cc

@@ -28,9 +28,12 @@
 
 namespace {
 
-const char* const kTestUsers[] = {"test-user1@consumer.example.com",
-                                  "test-user2@consumer.example.com",
-                                  "test-user3@consumer.example.com"};
+struct {
+  const char* email;
+  const char* gaia_id;
+} const kTestUsers[] = {{"test-user1@consumer.example.com", "1111111111"},
+                        {"test-user2@consumer.example.com", "2222222222"},
+                        {"test-user3@consumer.example.com", "3333333333"}};
 
 // Helper class to wait for user adding screen to finish.
 class UserAddingScreenWaiter : public UserAddingScreen::Observer {
@@ -93,7 +96,8 @@
   EXPECT_EQ(0u, manager->sessions().size());
 
   // Login via fake gaia to add a new user.
-  fake_gaia_.SetFakeMergeSessionParams(kTestUsers[0], "fake_sid", "fake_lsid");
+  fake_gaia_.SetFakeMergeSessionParams(kTestUsers[0].email, "fake_sid",
+                                       "fake_lsid");
   StartSignInScreen();
 
   content::WindowedNotificationObserver session_start_waiter(
@@ -102,7 +106,7 @@
 
   WebUILoginDisplay* login_display = static_cast<WebUILoginDisplay*>(
       ExistingUserController::current_controller()->login_display());
-  login_display->ShowSigninScreenForCreds(kTestUsers[0], "fake_password");
+  login_display->ShowSigninScreenForCreds(kTestUsers[0].email, "fake_password");
 
   session_start_waiter.Wait();
 
@@ -112,8 +116,8 @@
 }
 
 IN_PROC_BROWSER_TEST_F(ChromeSessionManagerTest, PRE_LoginExistingUsers) {
-  for (auto* user : kTestUsers) {
-    RegisterUser(user);
+  for (const auto& user : kTestUsers) {
+    RegisterUser(AccountId::FromUserEmailGaiaId(user.email, user.gaia_id));
   }
   StartupUtils::MarkOobeCompleted();
 }
@@ -126,9 +130,12 @@
             manager->session_state());
   EXPECT_EQ(0u, manager->sessions().size());
 
+  std::vector<AccountId> test_users;
+  test_users.push_back(AccountId::FromUserEmailGaiaId(kTestUsers[0].email,
+                                                      kTestUsers[0].gaia_id));
   // Verify that session state is ACTIVE with one user session after signing
   // in a user.
-  LoginUser(kTestUsers[0]);
+  LoginUser(test_users[0]);
   EXPECT_EQ(session_manager::SessionState::ACTIVE, manager->session_state());
   EXPECT_EQ(1u, manager->sessions().size());
 
@@ -142,7 +149,9 @@
     // Verify that session state is ACTIVE with 1+i user sessions after user
     // is added and new user session is started..
     UserAddingScreenWaiter waiter;
-    AddUser(kTestUsers[i]);
+    test_users.push_back(AccountId::FromUserEmailGaiaId(kTestUsers[i].email,
+                                                        kTestUsers[i].gaia_id));
+    AddUser(test_users.back());
     waiter.Wait();
     base::RunLoop().RunUntilIdle();
 
@@ -151,10 +160,9 @@
   }
 
   // Verify that session manager has the correct user session info.
-  ASSERT_EQ(arraysize(kTestUsers), manager->sessions().size());
-  for (size_t i = 0; i < arraysize(kTestUsers); ++i) {
-    EXPECT_EQ(kTestUsers[i],
-              manager->sessions()[i].user_account_id.GetUserEmail());
+  ASSERT_EQ(test_users.size(), manager->sessions().size());
+  for (size_t i = 0; i < test_users.size(); ++i) {
+    EXPECT_EQ(test_users[i], manager->sessions()[i].user_account_id);
   }
 }
 

diff --git a/chrome/browser/chromeos/login/session_login_browsertest.cc b/chrome/browser/chromeos/login/session_login_browsertest.cc
index 6f75f5b7..141be7f 100644
--- a/chrome/browser/chromeos/login/session_login_browsertest.cc
+++ b/chrome/browser/chromeos/login/session_login_browsertest.cc

@@ -21,7 +21,8 @@
 
 namespace {
 
-const char kTestUser[] = "test-user@gmail.com";
+constexpr char kTestUser[] = "test-user@gmail.com";
+constexpr char kTestUserGaiaId[] = "1234567890";
 
 }  // namespace
 
@@ -37,7 +38,7 @@
 };
 
 IN_PROC_BROWSER_TEST_F(BrowserLoginTest, PRE_BrowserActive) {
-  RegisterUser(kTestUser);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser, kTestUserGaiaId));
   EXPECT_EQ(session_manager::SessionState::OOBE,
             session_manager::SessionManager::Get()->session_state());
   chromeos::StartupUtils::MarkOobeCompleted();
@@ -46,7 +47,7 @@
 IN_PROC_BROWSER_TEST_F(BrowserLoginTest, BrowserActive) {
   EXPECT_EQ(session_manager::SessionState::LOGIN_PRIMARY,
             session_manager::SessionManager::Get()->session_state());
-  LoginUser(kTestUser);
+  LoginUser(AccountId::FromUserEmailGaiaId(kTestUser, kTestUserGaiaId));
   EXPECT_EQ(session_manager::SessionState::ACTIVE,
             session_manager::SessionManager::Get()->session_state());
 

diff --git a/chrome/browser/chromeos/login/supervised/supervised_user_test_base.cc b/chrome/browser/chromeos/login/supervised/supervised_user_test_base.cc
index f81559d2..50bd0c6 100644
--- a/chrome/browser/chromeos/login/supervised/supervised_user_test_base.cc
+++ b/chrome/browser/chromeos/login/supervised/supervised_user_test_base.cc

@@ -305,8 +305,10 @@
 }
 
 void SupervisedUserTestBase::PrepareUsers() {
-  RegisterUser(kTestManager);
-  RegisterUser(kTestOtherUser);
+  RegisterUser(
+      AccountId::FromUserEmailGaiaId(kTestManager, kTestManagerGaiaId));
+  RegisterUser(
+      AccountId::FromUserEmailGaiaId(kTestOtherUser, kTestOtherUserGaiaId));
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -351,8 +353,8 @@
 
   // Next button is now enabled.
   JSExpect("!$('supervised-user-creation-next-button').disabled");
-  UserContext user_context(AccountId::FromUserEmailGaiaId(
-      kTestManager, GetGaiaIDForUserID(kTestManager)));
+  UserContext user_context(
+      AccountId::FromUserEmailGaiaId(kTestManager, kTestManagerGaiaId));
   user_context.SetKey(Key(kTestManagerPassword));
   SetExpectedCredentials(user_context);
 
@@ -435,7 +437,7 @@
       ChromeUserManager::Get()->GetSupervisedUserManager())
       ->CheckForFirstRun(user->GetAccountId().GetUserEmail());
 
-  LoginUser(user->GetAccountId().GetUserEmail());
+  LoginUser(user->GetAccountId());
   if (check_homedir_calls)
     ::testing::Mock::VerifyAndClearExpectations(mock_homedir_methods_);
   Profile* profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
@@ -453,7 +455,7 @@
   // Created supervised user have to be first in a list.
   const user_manager::User* user =
       user_manager::UserManager::Get()->GetUsers().at(user_index);
-  LoginUser(user->GetAccountId().GetUserEmail());
+  LoginUser(user->GetAccountId());
   Profile* profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
   shared_settings_adapter_.reset(
       new SupervisedUsersSharedSettingsSyncTestAdapter(profile));

diff --git a/chrome/browser/chromeos/login/supervised/supervised_user_test_base.h b/chrome/browser/chromeos/login/supervised/supervised_user_test_base.h
index 581818c..9c7bec9 100644
--- a/chrome/browser/chromeos/login/supervised/supervised_user_test_base.h
+++ b/chrome/browser/chromeos/login/supervised/supervised_user_test_base.h

@@ -23,12 +23,14 @@
 
 namespace chromeos {
 
-const char kTestManager[] = "test-manager@gmail.com";
-const char kTestOtherUser[] = "test-user@gmail.com";
+constexpr char kTestManager[] = "test-manager@gmail.com";
+constexpr char kTestManagerGaiaId[] = "0001110001";
+constexpr char kTestOtherUser[] = "test-user@gmail.com";
+constexpr char kTestOtherUserGaiaId[] = "0002220001";
 
-const char kTestManagerPassword[] = "password";
-const char kTestSupervisedUserDisplayName[] = "John Doe";
-const char kTestSupervisedUserPassword[] = "simplepassword";
+constexpr char kTestManagerPassword[] = "password";
+constexpr char kTestSupervisedUserDisplayName[] = "John Doe";
+constexpr char kTestSupervisedUserPassword[] = "simplepassword";
 
 class SupervisedUsersSyncTestAdapter {
  public:

diff --git a/chrome/browser/chromeos/login/ui/user_adding_screen_browsertest.cc b/chrome/browser/chromeos/login/ui/user_adding_screen_browsertest.cc
index da8d11b..d5287ea7 100644
--- a/chrome/browser/chromeos/login/ui/user_adding_screen_browsertest.cc
+++ b/chrome/browser/chromeos/login/ui/user_adding_screen_browsertest.cc

@@ -26,19 +26,23 @@
 
 using namespace testing;
 
-namespace {
-
-const char* const kTestUsers[] = {
-    "test-user1@gmail.com", "test-user2@gmail.com", "test-user3@gmail.com"};
-
-}  // anonymous namespace
-
 namespace chromeos {
 
 class UserAddingScreenTest : public LoginManagerTest,
                              public UserAddingScreen::Observer {
  public:
-  UserAddingScreenTest() : LoginManagerTest(false) {}
+  UserAddingScreenTest() : LoginManagerTest(false) {
+    struct {
+      const char* email;
+      const char* gaia_id;
+    } const kTestUsers[] = {{"test-user1@gmail.com", "1111111111"},
+                            {"test-user2@gmail.com", "2222222222"},
+                            {"test-user3@gmail.com", "3333333333"}};
+    for (size_t i = 0; i < arraysize(kTestUsers); ++i) {
+      test_users_.emplace_back(AccountId::FromUserEmailGaiaId(
+          kTestUsers[i].email, kTestUsers[i].gaia_id));
+    }
+  }
 
   void SetUpInProcessBrowserTestFixture() override {
     LoginManagerTest::SetUpInProcessBrowserTestFixture();
@@ -88,6 +92,8 @@
 
   int user_adding_finished() { return user_adding_finished_; }
 
+  std::vector<AccountId> test_users_;
+
  private:
   int user_adding_started_ = 0;
   int user_adding_finished_ = 0;
@@ -99,9 +105,9 @@
 };
 
 IN_PROC_BROWSER_TEST_F(UserAddingScreenTest, PRE_CancelAdding) {
-  RegisterUser(kTestUsers[0]);
-  RegisterUser(kTestUsers[1]);
-  RegisterUser(kTestUsers[2]);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
+  RegisterUser(test_users_[2]);
   StartupUtils::MarkOobeCompleted();
 }
 
@@ -111,7 +117,7 @@
   EXPECT_EQ(session_manager::SessionState::LOGIN_PRIMARY,
             session_manager::SessionManager::Get()->session_state());
 
-  LoginUser(kTestUsers[0]);
+  LoginUser(test_users_[0]);
   EXPECT_EQ(1u, user_manager::UserManager::Get()->GetLoggedInUsers().size());
   EXPECT_EQ(session_manager::SessionState::ACTIVE,
             session_manager::SessionManager::Get()->session_state());
@@ -131,23 +137,22 @@
 
   EXPECT_TRUE(LoginDisplayHost::default_host() == nullptr);
   EXPECT_EQ(1u, user_manager::UserManager::Get()->GetLoggedInUsers().size());
-  EXPECT_EQ(kTestUsers[0], user_manager::UserManager::Get()
-                               ->GetActiveUser()
-                               ->GetAccountId()
-                               .GetUserEmail());
+  EXPECT_EQ(test_users_[0],
+            user_manager::UserManager::Get()->GetActiveUser()->GetAccountId());
 }
 
 IN_PROC_BROWSER_TEST_F(UserAddingScreenTest, PRE_AddingSeveralUsers) {
-  RegisterUser(kTestUsers[0]);
-  RegisterUser(kTestUsers[1]);
-  RegisterUser(kTestUsers[2]);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
+  RegisterUser(test_users_[2]);
   StartupUtils::MarkOobeCompleted();
 }
 
 IN_PROC_BROWSER_TEST_F(UserAddingScreenTest, AddingSeveralUsers) {
   EXPECT_EQ(session_manager::SessionState::LOGIN_PRIMARY,
             session_manager::SessionManager::Get()->session_state());
-  LoginUser(kTestUsers[0]);
+
+  LoginUser(test_users_[0]);
   EXPECT_EQ(session_manager::SessionState::ACTIVE,
             session_manager::SessionManager::Get()->session_state());
 
@@ -159,7 +164,7 @@
     EXPECT_EQ(i, user_adding_started());
     EXPECT_EQ(session_manager::SessionState::LOGIN_SECONDARY,
               session_manager::SessionManager::Get()->session_state());
-    AddUser(kTestUsers[i]);
+    AddUser(test_users_[i]);
     WaitUntilUserAddingFinishedOrCancelled();
     content::RunAllPendingInMessageLoop();
     EXPECT_EQ(i, user_adding_finished());
@@ -203,12 +208,12 @@
                     MultiProfileUserController::kBehaviorUnrestricted);
   user_manager::UserList unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(1UL, unlock_users.size());
-  EXPECT_EQ(kTestUsers[0], unlock_users[0]->GetAccountId().GetUserEmail());
+  EXPECT_EQ(test_users_[0], unlock_users[0]->GetAccountId());
 
   prefs1->SetBoolean(prefs::kEnableAutoScreenLock, false);
   unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(1UL, unlock_users.size());
-  EXPECT_EQ(kTestUsers[0], unlock_users[0]->GetAccountId().GetUserEmail());
+  EXPECT_EQ(test_users_[0], unlock_users[0]->GetAccountId());
 
   // If all users have unrestricted policy then anyone can perform unlock.
   prefs1->SetString(prefs::kMultiProfileUserBehavior,
@@ -216,21 +221,21 @@
   unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(3UL, unlock_users.size());
   for (int i = 0; i < 3; ++i)
-    EXPECT_EQ(kTestUsers[i], unlock_users[i]->GetAccountId().GetUserEmail());
+    EXPECT_EQ(test_users_[i], unlock_users[i]->GetAccountId());
 
   // This preference doesn't affect list of unlock users.
   prefs2->SetBoolean(prefs::kEnableAutoScreenLock, true);
   unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(3UL, unlock_users.size());
   for (int i = 0; i < 3; ++i)
-    EXPECT_EQ(kTestUsers[i], unlock_users[i]->GetAccountId().GetUserEmail());
+    EXPECT_EQ(test_users_[i], unlock_users[i]->GetAccountId());
 
   // Now one of the users is unable to unlock.
   SetUserCanLock(user_manager->GetLoggedInUsers()[2], false);
   unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(2UL, unlock_users.size());
   for (int i = 0; i < 2; ++i)
-    EXPECT_EQ(kTestUsers[i], unlock_users[i]->GetAccountId().GetUserEmail());
+    EXPECT_EQ(test_users_[i], unlock_users[i]->GetAccountId());
   SetUserCanLock(user_manager->GetLoggedInUsers()[2], true);
 
   // Now one of the users has not-allowed policy.
@@ -242,18 +247,18 @@
   unlock_users = user_manager->GetUnlockUsers();
   ASSERT_EQ(2UL, unlock_users.size());
   for (int i = 0; i < 2; ++i)
-    EXPECT_EQ(kTestUsers[i], unlock_users[i]->GetAccountId().GetUserEmail());
+    EXPECT_EQ(test_users_[i], unlock_users[i]->GetAccountId());
 }
 
 IN_PROC_BROWSER_TEST_F(UserAddingScreenTest, PRE_ScreenVisibility) {
-  RegisterUser(kTestUsers[0]);
-  RegisterUser(kTestUsers[1]);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   StartupUtils::MarkOobeCompleted();
 }
 
 // Trying to catch http://crbug.com/362153.
 IN_PROC_BROWSER_TEST_F(UserAddingScreenTest, ScreenVisibility) {
-  LoginUser(kTestUsers[0]);
+  LoginUser(test_users_[0]);
 
   UserAddingScreen::Get()->Start();
   content::RunAllPendingInMessageLoop();

diff --git a/chrome/browser/chromeos/login/users/avatar/user_image_manager_browsertest.cc b/chrome/browser/chromeos/login/users/avatar/user_image_manager_browsertest.cc
index 6ce5dc5..41b32097 100644
--- a/chrome/browser/chromeos/login/users/avatar/user_image_manager_browsertest.cc
+++ b/chrome/browser/chromeos/login/users/avatar/user_image_manager_browsertest.cc

@@ -86,8 +86,10 @@
 // Because policy is not needed in some tests it is better to use e-mails that
 // are definitely not enterprise. This lets us to avoid faking of policy fetch
 // procedure.
-const char kTestUser1[] = "test-user@gmail.com";
-const char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser1[] = "test-user@gmail.com";
+constexpr char kTestUser1GaiaId[] = "1111111111";
+constexpr char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser2GaiaId[] = "2222222222";
 
 policy::CloudPolicyStore* GetStoreForUser(const user_manager::User* user) {
   Profile* profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
@@ -302,10 +304,12 @@
 
   std::unique_ptr<base::RunLoop> run_loop_;
 
-  const AccountId test_account_id1_ = AccountId::FromUserEmail(kTestUser1);
-  const AccountId test_account_id2_ = AccountId::FromUserEmail(kTestUser2);
+  const AccountId test_account_id1_ =
+      AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId);
+  const AccountId test_account_id2_ =
+      AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId);
   const AccountId enterprise_account_id_ =
-      AccountId::FromUserEmail(kEnterpriseUser1);
+      AccountId::FromUserEmailGaiaId(kEnterpriseUser1, kEnterpriseUser1GaiaId);
   const cryptohome::Identification cryptohome_id_ =
       cryptohome::Identification(enterprise_account_id_);
 
@@ -314,7 +318,7 @@
 };
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest, PRE_SaveAndLoadUserImage) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
 
   // Setup a user with JPEG image.
   run_loop_.reset(new base::RunLoop);
@@ -346,7 +350,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest, PRE_SaveUserDefaultImageIndex) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
 }
 
 // Verifies that SaveUserDefaultImageIndex() correctly sets and persists the
@@ -373,7 +377,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest, PRE_SaveUserImage) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
 }
 
 // Verifies that SaveUserImage() correctly sets and persists the chosen user
@@ -414,7 +418,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest, PRE_SaveUserImageFromFile) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
 }
 
 // Verifies that SaveUserImageFromFile() correctly sets and persists the chosen
@@ -484,7 +488,7 @@
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest,
                        PRE_SaveUserImageFromProfileImage) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -496,7 +500,7 @@
   ASSERT_TRUE(user);
 
   UserImageManagerImpl::IgnoreProfileDataDownloadDelayForTesting();
-  LoginUser(test_account_id1_.GetUserEmail());
+  LoginUser(test_account_id1_);
   Profile* profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
   SeedAccountTrackerService(test_account_id1_, profile);
 
@@ -530,7 +534,7 @@
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerTest,
                        PRE_ProfileImageDownloadDoesNotClobber) {
-  RegisterUser(test_account_id1_.GetUserEmail());
+  RegisterUser(test_account_id1_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -548,7 +552,7 @@
       default_user_image::kFirstDefaultImageIndex);
 
   UserImageManagerImpl::IgnoreProfileDataDownloadDelayForTesting();
-  LoginUser(test_account_id1_.GetUserEmail());
+  LoginUser(test_account_id1_);
   Profile* profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
   SeedAccountTrackerService(test_account_id1_, profile);
 
@@ -667,7 +671,7 @@
 };
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerPolicyTest, PRE_SetAndClear) {
-  RegisterUser(enterprise_account_id_.GetUserEmail());
+  RegisterUser(enterprise_account_id_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -680,7 +684,7 @@
       user_manager::UserManager::Get()->FindUser(enterprise_account_id_);
   ASSERT_TRUE(user);
 
-  LoginUser(enterprise_account_id_.GetUserEmail());
+  LoginUser(enterprise_account_id_);
   base::RunLoop().RunUntilIdle();
 
   policy::CloudPolicyStore* store = GetStoreForUser(user);
@@ -758,7 +762,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerPolicyTest, PRE_PolicyOverridesUser) {
-  RegisterUser(enterprise_account_id_.GetUserEmail());
+  RegisterUser(enterprise_account_id_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -770,7 +774,7 @@
       user_manager::UserManager::Get()->FindUser(enterprise_account_id_);
   ASSERT_TRUE(user);
 
-  LoginUser(enterprise_account_id_.GetUserEmail());
+  LoginUser(enterprise_account_id_);
   base::RunLoop().RunUntilIdle();
 
   policy::CloudPolicyStore* store = GetStoreForUser(user);
@@ -822,7 +826,7 @@
 
 IN_PROC_BROWSER_TEST_F(UserImageManagerPolicyTest,
                        PRE_UserDoesNotOverridePolicy) {
-  RegisterUser(enterprise_account_id_.GetUserEmail());
+  RegisterUser(enterprise_account_id_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -834,7 +838,7 @@
       user_manager::UserManager::Get()->FindUser(enterprise_account_id_);
   ASSERT_TRUE(user);
 
-  LoginUser(enterprise_account_id_.GetUserEmail());
+  LoginUser(enterprise_account_id_);
   base::RunLoop().RunUntilIdle();
 
   policy::CloudPolicyStore* store = GetStoreForUser(user);

diff --git a/chrome/browser/chromeos/login/users/user_manager_unittest.cc b/chrome/browser/chromeos/login/users/user_manager_unittest.cc
index 2fe119a..bd2f1e3 100644
--- a/chrome/browser/chromeos/login/users/user_manager_unittest.cc
+++ b/chrome/browser/chromeos/login/users/user_manager_unittest.cc

@@ -150,11 +150,11 @@
   }
 
   const AccountId owner_account_id_at_invalid_domain_ =
-      AccountId::FromUserEmail("owner@invalid.domain");
+      AccountId::FromUserEmailGaiaId("owner@invalid.domain", "1234567890");
   const AccountId account_id0_at_invalid_domain_ =
-      AccountId::FromUserEmail("user0@invalid.domain");
+      AccountId::FromUserEmailGaiaId("user0@invalid.domain", "0123456789");
   const AccountId account_id1_at_invalid_domain_ =
-      AccountId::FromUserEmail("user1@invalid.domain");
+      AccountId::FromUserEmailGaiaId("user1@invalid.domain", "9012345678");
 
  protected:
   std::unique_ptr<WallpaperControllerClient> wallpaper_controller_client_;
@@ -282,7 +282,8 @@
 
   // Clear the stored user data - when UserManager loads again, it should
   // migrate existing users by setting session_initialized to true for them.
-  user_manager::known_user::RemovePrefsForTesting((*users)[0]->GetAccountId());
+  user_manager::known_user::RemoveSetProfileEverInitializedPrefForTesting(
+      (*users)[0]->GetAccountId());
   ResetUserManager();
   users = &user_manager::UserManager::Get()->GetUsers();
   ASSERT_EQ(1U, users->size());

diff --git a/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_browsertest.cc b/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_browsertest.cc
index dabd2a8..caaa944f 100644
--- a/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_browsertest.cc
+++ b/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_browsertest.cc

@@ -54,15 +54,17 @@
 
 namespace {
 
-int kLargeWallpaperWidth = 256;
-int kLargeWallpaperHeight = chromeos::kLargeWallpaperMaxHeight;
-int kSmallWallpaperWidth = 256;
-int kSmallWallpaperHeight = chromeos::kSmallWallpaperMaxHeight;
+constexpr int kLargeWallpaperWidth = 256;
+const int kLargeWallpaperHeight = chromeos::kLargeWallpaperMaxHeight;
+constexpr int kSmallWallpaperWidth = 256;
+const int kSmallWallpaperHeight = chromeos::kSmallWallpaperMaxHeight;
 
-const char kTestUser1[] = "test1@domain.com";
-const char kTestUser1Hash[] = "test1@domain.com-hash";
-const char kTestUser2[] = "test2@domain.com";
-const char kTestUser2Hash[] = "test2@domain.com-hash";
+constexpr char kTestUser1[] = "test1@domain.com";
+constexpr char kTestUser1GaiaId[] = "0000000001";
+constexpr char kTestUser1Hash[] = "test1@domain.com-hash";
+constexpr char kTestUser2[] = "test2@domain.com";
+constexpr char kTestUser2GaiaId[] = "0000000002";
+constexpr char kTestUser2Hash[] = "test2@domain.com-hash";
 
 // Helper function to get wallpaper files id.
 wallpaper::WallpaperFilesId GetFilesId(const AccountId& account_id) {
@@ -206,8 +208,10 @@
   // wallpaper images.
   std::unique_ptr<base::ScopedTempDir> wallpaper_dir_;
 
-  const AccountId test_account_id1_ = AccountId::FromUserEmail(kTestUser1);
-  const AccountId test_account_id2_ = AccountId::FromUserEmail(kTestUser2);
+  const AccountId test_account_id1_ =
+      AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId);
+  const AccountId test_account_id2_ =
+      AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId);
 
   const wallpaper::WallpaperFilesId test_account1_wallpaper_files_id_ =
       wallpaper::WallpaperFilesId::FromString(kTestUser1Hash);

diff --git a/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_policy_browsertest.cc b/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_policy_browsertest.cc
index e9790412..de49627 100644
--- a/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_policy_browsertest.cc
+++ b/chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_policy_browsertest.cc

@@ -150,10 +150,12 @@
         wallpaper_change_count_(0),
         owner_key_util_(new ownership::MockOwnerKeyUtil()),
         fake_session_manager_client_(new FakeSessionManagerClient) {
-    testUsers_.push_back(
-        AccountId::FromUserEmail(LoginManagerTest::kEnterpriseUser1));
-    testUsers_.push_back(
-        AccountId::FromUserEmail(LoginManagerTest::kEnterpriseUser2));
+    testUsers_.push_back(AccountId::FromUserEmailGaiaId(
+        LoginManagerTest::kEnterpriseUser1,
+        LoginManagerTest::kEnterpriseUser1GaiaId));
+    testUsers_.push_back(AccountId::FromUserEmailGaiaId(
+        LoginManagerTest::kEnterpriseUser2,
+        LoginManagerTest::kEnterpriseUser2GaiaId));
   }
 
   std::unique_ptr<policy::UserPolicyBuilder> GetUserPolicyBuilder(
@@ -329,8 +331,8 @@
 };
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PRE_SetResetClear) {
-  RegisterUser(testUsers_[0].GetUserEmail());
-  RegisterUser(testUsers_[1].GetUserEmail());
+  RegisterUser(testUsers_[0]);
+  RegisterUser(testUsers_[1]);
   StartupUtils::MarkOobeCompleted();
 }
 
@@ -341,7 +343,7 @@
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, SetResetClear) {
   SetSystemSalt();
   wallpaper::WallpaperInfo info;
-  LoginUser(testUsers_[0].GetUserEmail());
+  LoginUser(testUsers_[0]);
   base::RunLoop().RunUntilIdle();
 
   // First user: Wait until default wallpaper has been loaded (happens
@@ -382,14 +384,14 @@
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest,
                        DISABLED_PRE_PRE_PRE_WallpaperOnLoginScreen) {
-  RegisterUser(testUsers_[0].GetUserEmail());
-  RegisterUser(testUsers_[1].GetUserEmail());
+  RegisterUser(testUsers_[0]);
+  RegisterUser(testUsers_[1]);
   StartupUtils::MarkOobeCompleted();
 }
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest,
                        DISABLED_PRE_PRE_WallpaperOnLoginScreen) {
-  LoginUser(testUsers_[0].GetUserEmail());
+  LoginUser(testUsers_[0]);
 
   // Wait until default wallpaper has been loaded.
   RunUntilWallpaperChangeCount(1);
@@ -404,7 +406,7 @@
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest,
                        DISABLED_PRE_WallpaperOnLoginScreen) {
-  LoginUser(testUsers_[1].GetUserEmail());
+  LoginUser(testUsers_[1]);
 
   // Wait until default wallpaper has been loaded.
   RunUntilWallpaperChangeCount(1);
@@ -434,13 +436,13 @@
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PRE_PRE_PersistOverLogout) {
   SetSystemSalt();
-  RegisterUser(testUsers_[0].GetUserEmail());
+  RegisterUser(testUsers_[0]);
   StartupUtils::MarkOobeCompleted();
 }
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PRE_PersistOverLogout) {
   SetSystemSalt();
-  LoginUser(testUsers_[0].GetUserEmail());
+  LoginUser(testUsers_[0]);
 
   // Wait until default wallpaper has been loaded.
   RunUntilWallpaperChangeCount(1);
@@ -455,7 +457,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PersistOverLogout) {
-  LoginUser(testUsers_[0].GetUserEmail());
+  LoginUser(testUsers_[0]);
 
   // Wait until wallpaper has been loaded.
   RunUntilWallpaperChangeCount(1);
@@ -464,7 +466,7 @@
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PRE_DevicePolicyTest) {
   SetSystemSalt();
-  RegisterUser(testUsers_[0].GetUserEmail());
+  RegisterUser(testUsers_[0]);
   StartupUtils::MarkOobeCompleted();
 }
 
@@ -486,7 +488,7 @@
 
   // Log in a test user and set the user wallpaper policy. The user policy
   // controlled wallpaper shows up in the user session.
-  LoginUser(testUsers_[0].GetUserEmail());
+  LoginUser(testUsers_[0]);
   InjectPolicy(0, kGreenImageFileName);
   RunUntilWallpaperChangeCount(3);
   EXPECT_EQ(kGreenImageColor, GetAverageWallpaperColor());

diff --git a/chrome/browser/chromeos/net/network_portal_detector_impl_browsertest.cc b/chrome/browser/chromeos/net/network_portal_detector_impl_browsertest.cc
index f9948acc..d8e968b 100644
--- a/chrome/browser/chromeos/net/network_portal_detector_impl_browsertest.cc
+++ b/chrome/browser/chromeos/net/network_portal_detector_impl_browsertest.cc

@@ -25,6 +25,7 @@
 #include "chromeos/network/portal_detector/network_portal_detector_strategy.h"
 #include "components/captive_portal/captive_portal_testing_utils.h"
 #include "components/prefs/pref_service.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "components/sync_preferences/pref_service_syncable.h"
 #include "content/public/test/test_utils.h"
 #include "dbus/object_path.h"
@@ -50,9 +51,10 @@
 const char* const kUserActionMetric =
     NetworkPortalNotificationController::kUserActionMetric;
 
-const char kTestUser[] = "test-user@gmail.com";
-const char kWifiServicePath[] = "/service/wifi";
-const char kWifiGuid[] = "wifi";
+constexpr char kTestUser[] = "test-user@gmail.com";
+constexpr char kTestUserGaiaId[] = "1234567890";
+constexpr char kWifiServicePath[] = "/service/wifi";
+constexpr char kWifiGuid[] = "wifi";
 
 void ErrorCallbackFunction(const std::string& error_name,
                            const std::string& error_message) {
@@ -110,7 +112,11 @@
       public captive_portal::CaptivePortalDetectorTestBase {
  public:
   NetworkPortalDetectorImplBrowserTest()
-      : LoginManagerTest(false), network_portal_detector_(NULL) {}
+      : LoginManagerTest(false),
+        test_account_id_(
+            AccountId::FromUserEmailGaiaId(kTestUser, kTestUserGaiaId)),
+        network_portal_detector_(NULL) {}
+
   ~NetworkPortalDetectorImplBrowserTest() override {}
 
   void SetUpOnMainThread() override {
@@ -163,6 +169,9 @@
         ->GetDialogForTesting();
   }
 
+ protected:
+  AccountId test_account_id_;
+
  private:
   NetworkPortalDetectorImpl* network_portal_detector_;
 
@@ -171,7 +180,7 @@
 
 IN_PROC_BROWSER_TEST_F(NetworkPortalDetectorImplBrowserTest,
                        PRE_InSessionDetection) {
-  RegisterUser(kTestUser);
+  RegisterUser(test_account_id_);
   StartupUtils::MarkOobeCompleted();
   ASSERT_EQ(PortalDetectorStrategy::STRATEGY_ID_LOGIN_SCREEN, strategy()->Id());
 }
@@ -187,7 +196,7 @@
   EnumHistogramChecker action_checker(
       kUserActionMetric, Controller::USER_ACTION_METRIC_COUNT, NULL);
 
-  LoginUser(kTestUser);
+  LoginUser(test_account_id_);
   content::RunAllPendingInMessageLoop();
 
   // User connects to wifi.
@@ -250,7 +259,7 @@
   EnumHistogramChecker action_checker(
       kUserActionMetric, Controller::USER_ACTION_METRIC_COUNT, nullptr);
 
-  LoginUser(kTestUser);
+  LoginUser(test_account_id_);
   content::RunAllPendingInMessageLoop();
 
   SetIgnoreNoNetworkForTesting();
@@ -292,7 +301,7 @@
 
 IN_PROC_BROWSER_TEST_P(NetworkPortalDetectorImplBrowserTestIgnoreProxy,
                        PRE_TestWithPreference) {
-  RegisterUser(kTestUser);
+  RegisterUser(test_account_id_);
   StartupUtils::MarkOobeCompleted();
   EXPECT_EQ(PortalDetectorStrategy::STRATEGY_ID_LOGIN_SCREEN, strategy()->Id());
 }

diff --git a/chrome/browser/chromeos/policy/affiliation_test_helper.cc b/chrome/browser/chromeos/policy/affiliation_test_helper.cc
index 27b051a..912166d 100644
--- a/chrome/browser/chromeos/policy/affiliation_test_helper.cc
+++ b/chrome/browser/chromeos/policy/affiliation_test_helper.cc

@@ -32,6 +32,9 @@
 #include "components/policy/core/common/cloud/policy_builder.h"
 #include "components/prefs/pref_service.h"
 #include "components/prefs/scoped_user_pref_update.h"
+#include "components/signin/core/account_id/account_id.h"
+#include "components/user_manager/known_user.h"
+#include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/test/test_utils.h"
 #include "crypto/rsa_private_key.h"
@@ -41,8 +44,9 @@
 
 namespace affiliation_test_helper {
 
-const char kFakeRefreshToken[] = "fake-refresh-token";
-const char kEnterpriseUser[] = "testuser@example.com";
+constexpr char kFakeRefreshToken[] = "fake-refresh-token";
+constexpr char kEnterpriseUserEmail[] = "testuser@example.com";
+constexpr char kEnterpriseUserGaiaId[] = "01234567890";
 
 void SetUserKeys(policy::UserPolicyBuilder* user_policy) {
   const AccountId account_id =
@@ -97,21 +101,24 @@
       cryptohome::Identification(account_id), user_policy->GetBlob());
 }
 
-void PreLoginUser(const std::string& user_id) {
+void PreLoginUser(const AccountId& account_id) {
   ListPrefUpdate users_pref(g_browser_process->local_state(), "LoggedInUsers");
-  users_pref->AppendIfNotPresent(base::MakeUnique<base::Value>(user_id));
+  users_pref->AppendIfNotPresent(
+      base::MakeUnique<base::Value>(account_id.GetUserEmail()));
+  if (user_manager::UserManager::IsInitialized())
+    user_manager::known_user::SetProfileEverInitialized(account_id, false);
+
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
-void LoginUser(const std::string& user_id) {
+void LoginUser(const AccountId& account_id) {
   chromeos::test::UserSessionManagerTestApi session_manager_test_api(
       chromeos::UserSessionManager::GetInstance());
   session_manager_test_api.SetShouldObtainTokenHandleInTests(false);
 
-  chromeos::UserContext user_context(
-      AccountId::FromUserEmailGaiaId(user_id, "gaia-id-" + user_id));
+  chromeos::UserContext user_context(account_id);
   user_context.SetKey(chromeos::Key("password"));
-  if (user_id == kEnterpriseUser) {
+  if (account_id.GetUserEmail() == kEnterpriseUserEmail) {
     user_context.SetRefreshToken(kFakeRefreshToken);
   }
   chromeos::ExistingUserController* controller =
@@ -130,7 +137,8 @@
     if ((*it)->GetAccountId() == user_context.GetAccountId())
       return;
   }
-  ADD_FAILURE() << user_id << " was not added via PreLoginUser()";
+  ADD_FAILURE() << account_id.Serialize()
+                << " was not added via PreLoginUser()";
 }
 
 void AppendCommandLineSwitchesForLoginManager(base::CommandLine* command_line) {

diff --git a/chrome/browser/chromeos/policy/affiliation_test_helper.h b/chrome/browser/chromeos/policy/affiliation_test_helper.h
index d379d829..d875609 100644
--- a/chrome/browser/chromeos/policy/affiliation_test_helper.h
+++ b/chrome/browser/chromeos/policy/affiliation_test_helper.h

@@ -9,6 +9,8 @@
 #include <string>
 #include "components/policy/core/common/cloud/policy_builder.h"
 
+class AccountId;
+
 namespace base {
 class CommandLine;
 }  // namespace base
@@ -87,19 +89,21 @@
     const std::string& user_email,
     const std::set<std::string>& user_affiliation_ids);
 
-// Registers the user with the given |user_id| on the device and marks OOBE
+// Registers the user with the given |account_id| on the device and marks OOBE
 // as completed. This method should be called in PRE_* test.
-void PreLoginUser(const std::string& user_id);
+void PreLoginUser(const AccountId& account_id);
 
-// Log in user with |user_id|. User should be registered using PreLoginUser().
-void LoginUser(const std::string& user_id);
+// Log in user with |account_id|. User should be registered using
+// PreLoginUser().
+void LoginUser(const AccountId& user_id);
 
 // Set necessary for login command line switches. Execute it in
 // SetUpCommandLine().
 void AppendCommandLineSwitchesForLoginManager(base::CommandLine* command_line);
 
 extern const char kFakeRefreshToken[];
-extern const char kEnterpriseUser[];
+extern const char kEnterpriseUserEmail[];
+extern const char kEnterpriseUserGaiaId[];
 
 }  // namespace affiliation_test_helper
 

diff --git a/chrome/browser/chromeos/policy/unaffiliated_arc_allowed_browsertest.cc b/chrome/browser/chromeos/policy/unaffiliated_arc_allowed_browsertest.cc
index 2868363..c186001 100644
--- a/chrome/browser/chromeos/policy/unaffiliated_arc_allowed_browsertest.cc
+++ b/chrome/browser/chromeos/policy/unaffiliated_arc_allowed_browsertest.cc

@@ -31,9 +31,10 @@
 
 namespace {
 
-const char kAffiliatedUser[] = "affiliated-user@example.com";
-const char kAffiliationID[] = "some-affiliation-id";
-const char kAnotherAffiliationID[] = "another-affiliation-id";
+constexpr char kAffiliatedUserEmail[] = "affiliated-user@example.com";
+constexpr char kAffiliatedUserGaiaId[] = "affiliated-user@example.com";
+constexpr char kAffiliationID[] = "some-affiliation-id";
+constexpr char kAnotherAffiliationID[] = "another-affiliation-id";
 
 struct Params {
   explicit Params(bool affiliated) : affiliated_(affiliated) {}
@@ -46,7 +47,12 @@
     : public DevicePolicyCrosBrowserTest,
       public ::testing::WithParamInterface<Params> {
  public:
-  UnaffiliatedArcAllowedTest() { set_exit_when_last_browser_closes(false); }
+  UnaffiliatedArcAllowedTest()
+      : affiliated_account_id_(
+            AccountId::FromUserEmailGaiaId(kAffiliatedUserEmail,
+                                           kAffiliatedUserGaiaId)) {
+    set_exit_when_last_browser_closes(false);
+  }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
     DevicePolicyCrosBrowserTest::SetUpCommandLine(command_line);
@@ -72,8 +78,8 @@
       user_affiliation_ids.insert(kAnotherAffiliationID);
 
     affiliation_test_helper::SetUserAffiliationIDs(
-        &user_policy, session_manager_client(), kAffiliatedUser,
-        user_affiliation_ids);
+        &user_policy, session_manager_client(),
+        affiliated_account_id_.GetUserEmail(), user_affiliation_ids);
   }
 
   void TearDownOnMainThread() override {
@@ -104,18 +110,20 @@
     run_loop.Run();
   }
 
+  const AccountId affiliated_account_id_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(UnaffiliatedArcAllowedTest);
 };
 
 IN_PROC_BROWSER_TEST_P(UnaffiliatedArcAllowedTest, PRE_ProfileTest) {
-  affiliation_test_helper::PreLoginUser(kAffiliatedUser);
+  affiliation_test_helper::PreLoginUser(affiliated_account_id_);
 }
 
 IN_PROC_BROWSER_TEST_P(UnaffiliatedArcAllowedTest, ProfileTest) {
-  affiliation_test_helper::LoginUser(kAffiliatedUser);
-  const user_manager::User* user = user_manager::UserManager::Get()->FindUser(
-      AccountId::FromUserEmail(kAffiliatedUser));
+  affiliation_test_helper::LoginUser(affiliated_account_id_);
+  const user_manager::User* user =
+      user_manager::UserManager::Get()->FindUser(affiliated_account_id_);
   const Profile* profile =
       chromeos::ProfileHelper::Get()->GetProfileByUser(user);
   const bool affiliated = GetParam().affiliated_;

diff --git a/chrome/browser/chromeos/policy/user_affiliation_browsertest.cc b/chrome/browser/chromeos/policy/user_affiliation_browsertest.cc
index ebdf387..7a49cb6a 100644
--- a/chrome/browser/chromeos/policy/user_affiliation_browsertest.cc
+++ b/chrome/browser/chromeos/policy/user_affiliation_browsertest.cc

@@ -12,6 +12,7 @@
 #include "chromeos/dbus/fake_session_manager_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/policy/core/common/cloud/device_management_service.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/test/test_utils.h"
@@ -21,9 +22,11 @@
 
 namespace {
 
-const char kAffiliatedUser[] = "affiliated-user@example.com";
-const char kAffiliationID[] = "some-affiliation-id";
-const char kAnotherAffiliationID[] = "another-affiliation-id";
+constexpr char kAffiliatedUser[] = "affiliated-user@example.com";
+constexpr char kAffiliatedUserGaiaId[] = "1234567890";
+constexpr char kAffiliationID[] = "some-affiliation-id";
+constexpr char kAnotherAffiliationID[] = "another-affiliation-id";
+
 struct Params {
   explicit Params(bool affiliated) : affiliated_(affiliated) {}
   bool affiliated_;
@@ -35,7 +38,11 @@
     : public InProcessBrowserTest,
       public ::testing::WithParamInterface<Params> {
  public:
-  UserAffiliationBrowserTest() { set_exit_when_last_browser_closes(false); }
+  UserAffiliationBrowserTest()
+      : account_id_(AccountId::FromUserEmailGaiaId(kAffiliatedUser,
+                                                   kAffiliatedUserGaiaId)) {
+    set_exit_when_last_browser_closes(false);
+  }
 
  protected:
   // InProcessBrowserTest
@@ -67,27 +74,28 @@
       user_affiliation_ids.insert(kAnotherAffiliationID);
     }
     affiliation_test_helper::SetUserAffiliationIDs(
-        &user_policy, fake_session_manager_client, kAffiliatedUser,
+        &user_policy, fake_session_manager_client, account_id_.GetUserEmail(),
         user_affiliation_ids);
 
     // Set retry delay to prevent timeouts.
     policy::DeviceManagementService::SetRetryDelayForTesting(0);
   }
 
+  const AccountId account_id_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(UserAffiliationBrowserTest);
 };
 
 IN_PROC_BROWSER_TEST_P(UserAffiliationBrowserTest, PRE_Affiliated) {
-  affiliation_test_helper::PreLoginUser(kAffiliatedUser);
+  affiliation_test_helper::PreLoginUser(account_id_);
 }
 
 IN_PROC_BROWSER_TEST_P(UserAffiliationBrowserTest, Affiliated) {
-  affiliation_test_helper::LoginUser(kAffiliatedUser);
-  EXPECT_EQ(GetParam().affiliated_,
-            user_manager::UserManager::Get()
-                ->FindUser(AccountId::FromUserEmail(kAffiliatedUser))
-                ->IsAffiliated());
+  affiliation_test_helper::LoginUser(account_id_);
+  EXPECT_EQ(
+      GetParam().affiliated_,
+      user_manager::UserManager::Get()->FindUser(account_id_)->IsAffiliated());
 }
 
 INSTANTIATE_TEST_CASE_P(AffiliationCheck,

diff --git a/chrome/browser/chromeos/preferences_chromeos_browsertest.cc b/chrome/browser/chromeos/preferences_chromeos_browsertest.cc
index 3c59ca5..e9e516eb 100644
--- a/chrome/browser/chromeos/preferences_chromeos_browsertest.cc
+++ b/chrome/browser/chromeos/preferences_chromeos_browsertest.cc

@@ -42,19 +42,18 @@
 
 namespace chromeos {
 
-namespace {
-
-const char* const kTestUsers[] = {"test-user1@gmail.com",
-                                  "test-user2@gmail.com"};
-
-}  // namespace
-
 class PreferencesTest : public LoginManagerTest {
  public:
   PreferencesTest()
       : LoginManagerTest(true), input_settings_(nullptr), keyboard_(nullptr) {
+    struct {
+      const char* email;
+      const char* gaia_id;
+    } const kTestUsers[] = {{"test-user1@gmail.com", "1111111111"},
+                            {"test-user2@gmail.com", "2222222222"}};
     for (size_t i = 0; i < arraysize(kTestUsers); ++i) {
-      test_users_.push_back(AccountId::FromUserEmail(kTestUsers[i]));
+      test_users_.push_back(AccountId::FromUserEmailGaiaId(
+          kTestUsers[i].email, kTestUsers[i].gaia_id));
     }
   }
 
@@ -198,8 +197,8 @@
 };
 
 IN_PROC_BROWSER_TEST_F(PreferencesTest, PRE_MultiProfiles) {
-  RegisterUser(test_users_[0].GetUserEmail());
-  RegisterUser(test_users_[1].GetUserEmail());
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -208,7 +207,7 @@
 
   // Add first user and init its preferences. Check that corresponding
   // settings has been changed.
-  LoginUser(test_users_[0].GetUserEmail());
+  LoginUser(test_users_[0]);
   const user_manager::User* user1 = user_manager->FindUser(test_users_[0]);
   PrefService* prefs1 =
       ProfileHelper::Get()->GetProfileByUserUnsafe(user1)->GetPrefs();
@@ -219,7 +218,7 @@
   // Add second user and init its prefs with different values.
   UserAddingScreen::Get()->Start();
   content::RunAllPendingInMessageLoop();
-  AddUser(test_users_[1].GetUserEmail());
+  AddUser(test_users_[1]);
   content::RunAllPendingInMessageLoop();
   const user_manager::User* user2 = user_manager->FindUser(test_users_[1]);
   EXPECT_TRUE(user2->is_active());

diff --git a/chrome/browser/extensions/active_tab_unittest.cc b/chrome/browser/extensions/active_tab_unittest.cc
index c20a2e17..95b12728 100644
--- a/chrome/browser/extensions/active_tab_unittest.cc
+++ b/chrome/browser/extensions/active_tab_unittest.cc

@@ -463,8 +463,8 @@
   chromeos::WallpaperManager::Initialize();
   g_browser_process->local_state()->SetString(
       "PublicAccountPendingDataRemoval", user_email);
-  user_manager::UserManager::Get()->UserLoggedIn(
-      account_id, user_id_hash, true);
+  user_manager::UserManager::Get()->UserLoggedIn(account_id, user_id_hash,
+                                                 true);
 
   GURL google("http://www.google.com");
   NavigateAndCommit(google);

diff --git a/chrome/browser/extensions/api/braille_display_private/braille_display_private_apitest.cc b/chrome/browser/extensions/api/braille_display_private/braille_display_private_apitest.cc
index 3f507ef..8c71f0bb 100644
--- a/chrome/browser/extensions/api/braille_display_private/braille_display_private_apitest.cc
+++ b/chrome/browser/extensions/api/braille_display_private/braille_display_private_apitest.cc

@@ -38,7 +38,8 @@
 
 namespace {
 
-const char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserName[] = "owner@invalid.domain";
+constexpr char kTestUserGaiaId[] = "0123456789";
 
 // Used to make ReadKeys return an error.
 brlapi_keyCode_t kErrorKeyCode = BRLAPI_KEY_MAX;
@@ -338,7 +339,8 @@
   std::unique_ptr<ScreenLockerTester> tester(ScreenLocker::GetTester());
   // Log in.
   session_manager::SessionManager::Get()->CreateSession(
-      AccountId::FromUserEmail(kTestUserName), kTestUserName);
+      AccountId::FromUserEmailGaiaId(kTestUserName, kTestUserGaiaId),
+      kTestUserName);
   g_browser_process->profile_manager()->GetProfile(
       ProfileHelper::Get()->GetProfilePathByUserIdHash(kTestUserName));
   session_manager::SessionManager::Get()->SessionStarted();

diff --git a/chrome/browser/extensions/api/enterprise_device_attributes/enterprise_device_attributes_apitest.cc b/chrome/browser/extensions/api/enterprise_device_attributes/enterprise_device_attributes_apitest.cc
index f0d5b67..a83c8672 100644
--- a/chrome/browser/extensions/api/enterprise_device_attributes/enterprise_device_attributes_apitest.cc
+++ b/chrome/browser/extensions/api/enterprise_device_attributes/enterprise_device_attributes_apitest.cc

@@ -29,20 +29,21 @@
 
 namespace {
 
-const char kDeviceId[] = "device_id";
-const base::FilePath::CharType kTestExtensionDir[] =
+constexpr char kDeviceId[] = "device_id";
+constexpr base::FilePath::CharType kTestExtensionDir[] =
     FILE_PATH_LITERAL("extensions/api_test/enterprise_device_attributes");
-const base::FilePath::CharType kUpdateManifestFileName[] =
+constexpr base::FilePath::CharType kUpdateManifestFileName[] =
     FILE_PATH_LITERAL("update_manifest.xml");
 
-const char kAffiliatedUserEmail[] = "user@example.com";
-const char kAffiliationID[] = "some-affiliation-id";
-const char kAnotherAffiliationID[] = "another-affiliation-id";
+constexpr char kAffiliatedUserEmail[] = "user@example.com";
+constexpr char kAffiliatedUserGaiaId[] = "1029384756";
+constexpr char kAffiliationID[] = "some-affiliation-id";
+constexpr char kAnotherAffiliationID[] = "another-affiliation-id";
 
 // The managed_storage extension has a key defined in its manifest, so that
 // its extension ID is well-known and the policy system can push policies for
 // the extension.
-const char kTestExtensionID[] = "nbiliclbejdndfpchgkbmfoppjplbdok";
+constexpr char kTestExtensionID[] = "nbiliclbejdndfpchgkbmfoppjplbdok";
 
 struct Params {
   explicit Params(bool affiliated) : affiliated_(affiliated) {}
@@ -127,10 +128,8 @@
   void SetUpOnMainThread() override {
     const base::ListValue* users =
         g_browser_process->local_state()->GetList("LoggedInUsers");
-    if (!users->empty()) {
-      policy::affiliation_test_helper::LoginUser(
-          affiliated_account_id_.GetUserEmail());
-    }
+    if (!users->empty())
+      policy::affiliation_test_helper::LoginUser(affiliated_account_id_);
 
     ExtensionApiTest::SetUpOnMainThread();
   }
@@ -184,7 +183,8 @@
   }
 
   const AccountId affiliated_account_id_ =
-      AccountId::FromUserEmail(kAffiliatedUserEmail);
+      AccountId::FromUserEmailGaiaId(kAffiliatedUserEmail,
+                                     kAffiliatedUserGaiaId);
 
  private:
   policy::MockConfigurationPolicyProvider policy_provider_;
@@ -192,8 +192,7 @@
 };
 
 IN_PROC_BROWSER_TEST_P(EnterpriseDeviceAttributesTest, PRE_Success) {
-  policy::affiliation_test_helper::PreLoginUser(
-      affiliated_account_id_.GetUserEmail());
+  policy::affiliation_test_helper::PreLoginUser(affiliated_account_id_);
 }
 
 IN_PROC_BROWSER_TEST_P(EnterpriseDeviceAttributesTest, Success) {

diff --git a/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc b/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc
index 5269baa..a3661f06 100644
--- a/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc
+++ b/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc

@@ -162,7 +162,8 @@
 const char kAffiliationID[] = "some-affiliation-id";
 const char kTestUserinfoToken[] = "fake-userinfo-token";
 
-using policy::affiliation_test_helper::kEnterpriseUser;
+using policy::affiliation_test_helper::kEnterpriseUserEmail;
+using policy::affiliation_test_helper::kEnterpriseUserGaiaId;
 
 enum SystemToken {
   SYSTEM_TOKEN_EXISTS,
@@ -196,7 +197,9 @@
     : public ExtensionApiTest,
       public ::testing::WithParamInterface<Params> {
  public:
-  EnterprisePlatformKeysTest() {
+  EnterprisePlatformKeysTest()
+      : account_id_(AccountId::FromUserEmailGaiaId(kEnterpriseUserEmail,
+                                                   kEnterpriseUserGaiaId)) {
     // Command line should not be tweaked as if user is already logged in.
     set_chromeos_user_ = false;
     // We log in without running browser.
@@ -268,7 +271,7 @@
       user_affiliation_ids.insert(kAffiliationID);
       policy::UserPolicyBuilder user_policy;
       policy::affiliation_test_helper::SetUserAffiliationIDs(
-          &user_policy, fake_session_manager_client, kEnterpriseUser,
+          &user_policy, fake_session_manager_client, account_id_.GetUserEmail(),
           user_affiliation_ids);
     }
 
@@ -291,7 +294,7 @@
     token_info.scopes.insert(GaiaConstants::kOAuthWrapBridgeUserInfoScope);
     token_info.audience = GaiaUrls::GetInstance()->oauth2_chrome_client_id();
     token_info.token = kTestUserinfoToken;
-    token_info.email = kEnterpriseUser;
+    token_info.email = account_id_.GetUserEmail();
     fake_gaia_.IssueOAuthToken(
         policy::affiliation_test_helper::kFakeRefreshToken,
         token_info);
@@ -305,7 +308,7 @@
 
     // This condition is not held in PRE_ test.
     if (!users->empty())
-      policy::affiliation_test_helper::LoginUser(kEnterpriseUser);
+      policy::affiliation_test_helper::LoginUser(account_id_);
 
     if (GetParam().system_token_ == SYSTEM_TOKEN_EXISTS) {
       base::RunLoop loop;
@@ -419,6 +422,10 @@
         content::BrowserThread::UI, FROM_HERE, done_callback);
   }
 
+ protected:
+  const AccountId account_id_;
+
+ private:
   policy::DevicePolicyCrosTestHelper device_policy_test_helper_;
   std::unique_ptr<crypto::ScopedTestSystemNSSKeySlot> test_system_slot_;
   policy::MockConfigurationPolicyProvider policy_provider_;
@@ -429,7 +436,7 @@
 }  // namespace
 
 IN_PROC_BROWSER_TEST_P(EnterprisePlatformKeysTest, PRE_Basic) {
-  policy::affiliation_test_helper::PreLoginUser(kEnterpriseUser);
+  policy::affiliation_test_helper::PreLoginUser(account_id_);
 }
 
 IN_PROC_BROWSER_TEST_P(EnterprisePlatformKeysTest, Basic) {

diff --git a/chrome/browser/net/nss_context_chromeos_browsertest.cc b/chrome/browser/net/nss_context_chromeos_browsertest.cc
index a6def613..31d4b3c7 100644
--- a/chrome/browser/net/nss_context_chromeos_browsertest.cc
+++ b/chrome/browser/net/nss_context_chromeos_browsertest.cc

@@ -19,8 +19,10 @@
 
 namespace {
 
-const char kTestUser1[] = "test-user1@gmail.com";
-const char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser1[] = "test-user1@gmail.com";
+constexpr char kTestUser1GaiaId[] = "1111111111";
+constexpr char kTestUser2[] = "test-user2@gmail.com";
+constexpr char kTestUser2GaiaId[] = "2222222222";
 
 void NotCalledDbCallback(net::NSSCertDatabase* db) { ASSERT_TRUE(false); }
 
@@ -164,8 +166,8 @@
 
 IN_PROC_BROWSER_TEST_F(NSSContextChromeOSBrowserTest, PRE_TwoUsers) {
   // Initialization for ChromeOS multi-profile test infrastructure.
-  RegisterUser(kTestUser1);
-  RegisterUser(kTestUser2);
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  RegisterUser(AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -173,9 +175,11 @@
   user_manager::UserManager* user_manager = user_manager::UserManager::Get();
 
   // Log in first user and get their DB.
-  LoginUser(kTestUser1);
+  const AccountId account_id1(
+      AccountId::FromUserEmailGaiaId(kTestUser1, kTestUser1GaiaId));
+  LoginUser(account_id1);
   Profile* profile1 = chromeos::ProfileHelper::Get()->GetProfileByUserUnsafe(
-      user_manager->FindUser(AccountId::FromUserEmail(kTestUser1)));
+      user_manager->FindUser(account_id1));
   ASSERT_TRUE(profile1);
 
   DBTester tester1(profile1);
@@ -185,11 +189,14 @@
   UserAddingFinishObserver observer;
   chromeos::UserAddingScreen::Get()->Start();
   base::RunLoop().RunUntilIdle();
-  AddUser(kTestUser2);
+
+  const AccountId account_id2(
+      AccountId::FromUserEmailGaiaId(kTestUser2, kTestUser2GaiaId));
+  AddUser(account_id2);
   observer.WaitUntilUserAddingFinishedOrCancelled();
 
   Profile* profile2 = chromeos::ProfileHelper::Get()->GetProfileByUserUnsafe(
-      user_manager->FindUser(AccountId::FromUserEmail(kTestUser2)));
+      user_manager->FindUser(account_id2));
   ASSERT_TRUE(profile2);
 
   DBTester tester2(profile2);

diff --git a/chrome/browser/notifications/login_state_notification_blocker_chromeos_browsertest.cc b/chrome/browser/notifications/login_state_notification_blocker_chromeos_browsertest.cc
index a7516d71..5d162f82 100644
--- a/chrome/browser/notifications/login_state_notification_blocker_chromeos_browsertest.cc
+++ b/chrome/browser/notifications/login_state_notification_blocker_chromeos_browsertest.cc

@@ -22,9 +22,6 @@
 
 namespace {
 
-const char* kTestUsers[] = {"test-user@gmail.com",
-                            "test-user1@gmail.com"};
-
 class UserAddingFinishObserver : public chromeos::UserAddingScreen::Observer {
  public:
   UserAddingFinishObserver() {
@@ -64,7 +61,18 @@
       public message_center::MessageCenterObserver {
  public:
   LoginStateNotificationBlockerChromeOSBrowserTest()
-      : chromeos::LoginManagerTest(false) {}
+      : chromeos::LoginManagerTest(false) {
+    struct {
+      const char* email;
+      const char* gaia_id;
+    } const kTestUsers[] = {{"test-user@gmail.com", "1110001111"},
+                            {"test-user1@gmail.com", "1111111111"}};
+    for (size_t i = 0; i < arraysize(kTestUsers); ++i) {
+      test_users_.emplace_back(AccountId::FromUserEmailGaiaId(
+          kTestUsers[i].email, kTestUsers[i].gaia_id));
+    }
+  }
+
   ~LoginStateNotificationBlockerChromeOSBrowserTest() override {}
 
   void SetUpOnMainThread() override {
@@ -127,6 +135,8 @@
     return new_count == initial_count + 1;
   }
 
+  std::vector<AccountId> test_users_;
+
  private:
   int state_changed_count_ = 0;
 
@@ -138,8 +148,8 @@
 
 IN_PROC_BROWSER_TEST_F(LoginStateNotificationBlockerChromeOSBrowserTest,
                        PRE_BaseTest) {
-  RegisterUser(kTestUsers[0]);
-  RegisterUser(kTestUsers[1]);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -147,10 +157,10 @@
                        BaseTest) {
   message_center::NotifierId notifier_id(
       message_center::NotifierId::APPLICATION, "test-notifier");
-  notifier_id.profile_id = kTestUsers[0];
+  notifier_id.profile_id = test_users_[0].GetUserEmail();
 
   // Logged in as a normal user.
-  LoginUser(kTestUsers[0]);
+  LoginUser(test_users_[0]);
 
   // One state change from LoginStateNotificationBloker plus one state change
   // for the InactiveUserNotificationBlocker.
@@ -174,8 +184,8 @@
 
 IN_PROC_BROWSER_TEST_F(LoginStateNotificationBlockerChromeOSBrowserTest,
                        PRE_AlwaysAllowedNotifier) {
-  RegisterUser(kTestUsers[0]);
-  RegisterUser(kTestUsers[1]);
+  RegisterUser(test_users_[0]);
+  RegisterUser(test_users_[1]);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -185,10 +195,10 @@
   message_center::NotifierId notifier_id(
       message_center::NotifierId::SYSTEM_COMPONENT,
       ash::system_notifier::kNotifierDisplay);
-  notifier_id.profile_id = kTestUsers[0];
+  notifier_id.profile_id = test_users_[0].GetUserEmail();
 
   // Logged in as a normal user.
-  LoginUser(kTestUsers[0]);
+  LoginUser(test_users_[0]);
 
   // One state change from LoginStateNotificationBloker plus one state change
   // for the InactiveUserNotificationBlocker.

diff --git a/chrome/browser/profiles/profile_manager_unittest.cc b/chrome/browser/profiles/profile_manager_unittest.cc
index 972f8c0..fef20e4f 100644
--- a/chrome/browser/profiles/profile_manager_unittest.cc
+++ b/chrome/browser/profiles/profile_manager_unittest.cc

@@ -209,12 +209,13 @@
 #if defined(OS_CHROMEOS)
   // Helper function to register an user with id |user_id| and create profile
   // with a correct path.
-  void RegisterUser(const std::string& user_id) {
+  void RegisterUser(const AccountId& account_id) {
     chromeos::ProfileHelper* profile_helper = chromeos::ProfileHelper::Get();
     const std::string user_id_hash =
-        profile_helper->GetUserIdHashByUserIdForTesting(user_id);
-    user_manager::UserManager::Get()->UserLoggedIn(
-        AccountId::FromUserEmail(user_id), user_id_hash, false);
+        profile_helper->GetUserIdHashByUserIdForTesting(
+            account_id.GetUserEmail());
+    user_manager::UserManager::Get()->UserLoggedIn(account_id, user_id_hash,
+                                                   false);
     g_browser_process->profile_manager()->GetProfile(
         profile_helper->GetProfilePathByUserIdHash(user_id_hash));
   }
@@ -280,8 +281,10 @@
   EXPECT_EQ(expected_default.value(),
             profile_manager->GetInitialProfileDir().value());
 
-  const char kTestUserName[] = "test-user@example.com";
-  const AccountId test_account_id(AccountId::FromUserEmail(kTestUserName));
+  constexpr char kTestUserName[] = "test-user@example.com";
+  constexpr char kTestUserGaiaId[] = "0123456789";
+  const AccountId test_account_id(
+      AccountId::FromUserEmailGaiaId(kTestUserName, kTestUserGaiaId));
   chromeos::FakeChromeUserManager* user_manager =
       new chromeos::FakeChromeUserManager();
   user_manager::ScopedUserManager enabler(base::WrapUnique(user_manager));
@@ -322,10 +325,11 @@
 
   // User signs in but user profile loading has not started.
   const std::string user_id = "test-user@example.com";
+  const std::string gaia_id = "0123456789";
   const std::string user_id_hash =
       ProfileHelper::Get()->GetUserIdHashByUserIdForTesting(user_id);
   user_manager::UserManager::Get()->UserLoggedIn(
-      AccountId::FromUserEmail(user_id), user_id_hash, false);
+      AccountId::FromUserEmailGaiaId(user_id, gaia_id), user_id_hash, false);
 
   // Sign-in profile should be returned at this stage. Otherwise, login code
   // ends up in an invalid state. Strange things as in http://crbug.com/728683
@@ -608,9 +612,17 @@
     session_type_ = extensions::ScopedCurrentFeatureSessionType(
         extensions::GetCurrentFeatureSessionType());
 
-    RegisterUser(user_manager::kGuestUserName);
+    RegisterUser(GetFakeUserManager()->GetGuestAccountId());
 #endif
   }
+
+ private:
+#if defined(OS_CHROMEOS)
+  chromeos::FakeChromeUserManager* GetFakeUserManager() const {
+    return static_cast<chromeos::FakeChromeUserManager*>(
+        user_manager::UserManager::Get());
+  }
+#endif
 };
 
 TEST_F(ProfileManagerGuestTest, GetLastUsedProfileAllowedByPolicy) {
@@ -758,7 +770,8 @@
   // On CrOS, profile returned by GetLastUsedProfile is a sign-in profile that
   // is forced to be incognito. That's why we need to create at least one user
   // to get a regular profile.
-  RegisterUser("test-user@example.com");
+  RegisterUser(
+      AccountId::FromUserEmailGaiaId("test-user@example.com", "1234567890"));
 #endif
 
   Profile* profile = profile_manager->GetLastUsedProfileAllowedByPolicy();

diff --git a/chrome/browser/profiling_host/profiling_process_host.cc b/chrome/browser/profiling_host/profiling_process_host.cc
index 0adf8a8..82782b7d 100644
--- a/chrome/browser/profiling_host/profiling_process_host.cc
+++ b/chrome/browser/profiling_host/profiling_process_host.cc

@@ -154,6 +154,13 @@
 
 void UploadTraceToCrashServer(std::string file_contents,
                               std::string trigger_name) {
+  // Traces has been observed as small as 4k. Seems likely to be a bug. To
+  // account for all potentially too-small traces, we set the lower bounds to
+  // 512 bytes. The upper bounds is set to 300MB as an extra-high threshold,
+  // just in case something goes wrong.
+  UMA_HISTOGRAM_CUSTOM_COUNTS("OutOfProcessHeapProfiling.UploadTrace.Size",
+                              file_contents.size(), 512, 300 * 1024 * 1024, 50);
+
   base::Value rules_list(base::Value::Type::LIST);
   base::Value rule(base::Value::Type::DICTIONARY);
   rule.SetKey("rule", base::Value("MEMLOG"));
@@ -488,6 +495,8 @@
 
   auto finish_report_callback = base::BindOnce(
       [](std::string trigger_name, bool success, std::string trace) {
+        UMA_HISTOGRAM_BOOLEAN("OutOfProcessHeapProfiling.RecordTrace.Success",
+                              success);
         if (success) {
           UploadTraceToCrashServer(std::move(trace), std::move(trigger_name));
         }
@@ -549,10 +558,12 @@
     DCHECK(!dump_process_for_tracing_callback_);
     dump_process_for_tracing_callback_ = std::move(stop_tracing_closure);
   } else {
-    // Wait 10 seconds, then end the trace.
+    // Wait 30 seconds, then end the trace. 10 seconds has been observed to not
+    // be sufficient time for the profiling service to dump its data to the
+    // trace.
     base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE, std::move(stop_tracing_closure),
-        base::TimeDelta::FromSeconds(10));
+        base::TimeDelta::FromSeconds(30));
   }
 }
 

diff --git a/chrome/browser/resources/md_extensions/item.html b/chrome/browser/resources/md_extensions/item.html
index a832300..27f2390 100644
--- a/chrome/browser/resources/md_extensions/item.html
+++ b/chrome/browser/resources/md_extensions/item.html

@@ -26,10 +26,32 @@
   <template>
     <style include=
         "iron-flex cr-hidden-style cr-icons action-link paper-button-style">
+      .bounded-text,
+      .multiline-clippable-text,
+      .clippable-flex-text {
+        /** Ensure that the text does not overflow its container. */
+        overflow: hidden;
+        text-overflow: ellipsis;
+      }
+
+      .bounded-text,
+      .clippable-flex-text {
+        white-space: nowrap;
+      }
+
+      .clipppable-flex-text {
+        /**
+         * These labels can be arbitrarily long. We want to ensure that these
+         * shrink, rather than the neighboring content.
+         */
+        flex-shrink: 1;
+      }
+
       #icon-wrapper {
         align-self: flex-start;
         display: flex;
         padding: 6px;
+        position: relative;
       }
 
       #icon {
@@ -53,15 +75,16 @@
 
       #main {
         display: flex;
-        flex-grow: 1;
+        flex: 1;
         padding: 16px 20px 17px;
       }
 
       #content {
         -webkit-margin-start: 24px;
         display: flex;
+        flex: 1;
         flex-direction: column;
-        width: 100%;
+        overflow: hidden;
       }
 
       #name-and-version {
@@ -73,9 +96,13 @@
         -webkit-margin-end: 8px;
       }
 
-      #description,
+      #description {
+        flex: 1;
+      }
+
       #warnings {
-        flex-grow: 1;
+        color: var(--google-red-700);
+        flex: 1;
         margin-bottom: 8px;
       }
 
@@ -89,11 +116,25 @@
         font-weight: 400;
       }
 
+      #extension-id {
+        flex-shrink: 0;
+      }
+
+      #inspect-views {
+        display: flex;
+        white-space: nowrap;
+      }
+
+      #inspect-views > span {
+        -webkit-margin-end: 4px;
+      }
+
       #button-strip {
         /* Avoid ripple from overlapping container. */
         -webkit-margin-end: 20px;
         border-top: var(--cr-separator-line);
         box-sizing: border-box;
+        flex-shrink: 0;
         height: var(--cr-section-min-height);
         padding-bottom: 8px;
         padding-top: 8px;
@@ -108,10 +149,6 @@
         text-decoration: none;
       }
 
-      #icon-wrapper {
-        position: relative;
-      }
-
       #source-indicator {
         -webkit-margin-start: 24px;
         margin-top: 24px;
@@ -155,10 +192,6 @@
         -webkit-margin-end: 12px;
       }
 
-      #warnings {
-        color: var(--google-red-700);
-      }
-
       #blacklisted-warning:empty {
         display: none;
       }
@@ -192,13 +225,18 @@
           </paper-tooltip>
         </template>
         <div id="content">
-          <div id="name-and-version" class="layout horizontal center">
-            <div id="name">[[data.name]]</div>
-            <span id="version" hidden$="[[!inDevMode]]">
-              [[data.version]]
-            </span>
+          <!--Note: We wrap inspect-views in a div so that the outer div
+              doesn't shrink (because it's not display: flex).-->
+          <div>
+            <div id="name-and-version" class="layout horizontal center">
+              <div id="name" class="clippable-flex-text">[[data.name]]</div>
+              <span id="version" hidden$="[[!inDevMode]]">
+                [[data.version]]
+              </span>
+            </div>
           </div>
-          <div id="description" hidden$="[[hasWarnings_(data.*)]]">
+          <div id="description" class="multiline-clippable-text"
+              hidden$="[[hasWarnings_(data.*)]]">
             [[data.description]]
           </div>
           <template is="dom-if" if="[[hasWarnings_(data.*)]]">
@@ -221,19 +259,25 @@
             </div>
           </template>
           <template is="dom-if" if="[[inDevMode]]">
-            <div id="extension-id">[[data.id]]</div>
+            <div id="extension-id" class="bounded-text">[[data.id]]</div>
             <template is="dom-if"
                 if="[[!computeInspectViewsHidden_(data.views)]]">
-              <div id="inspect-views">
-                <span>$i18n{itemInspectViews}</span>
-                <a is="action-link" on-tap="onInspectTap_">
-                  [[computeFirstInspectLabel_(data.views)]]
-                </a>
-                <a is="action-link"
-                    hidden$="[[computeExtraViewsHidden_(data.views)]]"
-                    on-tap="onExtraInspectTap_">
-                  [[computeExtraInspectLabel_(data.views)]]
-                </a>
+              <!--Note: We wrap inspect-views in a div so that the outer div
+                  doesn't shrink (because it's not display: flex).-->
+              <div>
+                <div id="inspect-views">
+                  <span>$i18n{itemInspectViews}</span>
+                  <a class="clippable-flex-text" is="action-link"
+                      title="[[computeFirstInspectTitle_(data.views)]]"
+                      on-tap="onInspectTap_">
+                    [[computeFirstInspectLabel_(data.views)]]
+                  </a>
+                  <a is="action-link"
+                      hidden$="[[computeExtraViewsHidden_(data.views)]]"
+                      on-tap="onExtraInspectTap_">
+                    [[computeExtraInspectLabel_(data.views)]]
+                  </a>
+                </div>
               </div>
             </template>
           </template>

diff --git a/chrome/browser/resources/md_extensions/item.js b/chrome/browser/resources/md_extensions/item.js
index a433f35..37a95fc 100644
--- a/chrome/browser/resources/md_extensions/item.js
+++ b/chrome/browser/resources/md_extensions/item.js

@@ -273,18 +273,24 @@
      * @return {string}
      * @private
      */
-    computeFirstInspectLabel_: function() {
+    computeFirstInspectTitle_: function() {
       // Note: theoretically, this wouldn't be called without any inspectable
       // views (because it's in a dom-if="!computeInspectViewsHidden_()").
       // However, due to the recycling behavior of iron list, it seems that
       // sometimes it can. Even when it is, the UI behaves properly, but we
       // need to handle the case gracefully.
-      if (this.data.views.length == 0)
-        return '';
-      let label = extensions.computeInspectableViewLabel(this.data.views[0]);
-      if (this.data.views.length > 1)
-        label += ',';
-      return label;
+      return this.data.views.length > 0 ?
+          extensions.computeInspectableViewLabel(this.data.views[0]) :
+          '';
+    },
+
+    /**
+     * @return {string}
+     * @private
+     */
+    computeFirstInspectLabel_: function() {
+      let label = this.computeFirstInspectTitle_();
+      return label && this.data.views.length > 1 ? label + ',' : label;
     },
 
     /**

diff --git a/chrome/browser/resources/md_extensions/keyboard_shortcuts.html b/chrome/browser/resources/md_extensions/keyboard_shortcuts.html
index 854db355..5fcde2f5 100644
--- a/chrome/browser/resources/md_extensions/keyboard_shortcuts.html
+++ b/chrome/browser/resources/md_extensions/keyboard_shortcuts.html

@@ -20,17 +20,18 @@
       }
 
       .shortcut-card {
-        margin: 0 auto 16px auto;
-        max-width: var(--card-max-width);
-        min-width: var(--card-min-width);
-        width: 90%;
-      }
-
-      .shortcut-card {
         @apply --cr-primary-text;
         @apply --shadow-elevation-2dp;
         background-color: white;
+        margin: 0 auto 16px auto;
+        max-width: var(--card-max-width);
+        min-width: var(--card-min-width);
         padding-bottom: 8px;
+        width: 90%;
+      }
+
+      .shortcut-card:last-of-type {
+        margin-bottom: 64px;
       }
 
       #container {

diff --git a/chrome/browser/resources/media_router/elements/route_controls/route_controls.css b/chrome/browser/resources/media_router/elements/route_controls/route_controls.css
index c2e56bd6..42b845b 100644
--- a/chrome/browser/resources/media_router/elements/route_controls/route_controls.css
+++ b/chrome/browser/resources/media_router/elements/route_controls/route_controls.css

@@ -84,12 +84,9 @@
 }
 
 #hangouts-local-present-controls {
-  -webkit-font-smoothing: antialiased;
-  -webkit-tap-highlight-color: transparent;
   cursor: pointer;
   display: inline-block;
   float: right;
-  font-family: 'Roboto', 'Noto', sans-serif;
   padding-top: 10.5px;
   white-space: nowrap;
 }
@@ -105,16 +102,14 @@
   width: 249px;
 }
 
-#always-use-mirroring-checkbox {
-  --paper-checkbox-vertical-align: middle;
-  --paper-checkbox-label-spacing: 10%;
-  padding: 0.3em 0 0.3em 0;
-  width: 100%;
-}
-
-#media-remoting-enabled-controls {
+#mirroring-fullscreen-video-controls {
   display: inline-block;
   font-size: 0.8em;
-  margin: 2px 8px;
-  width: 100%;
+  margin: 15px 8px 3px 8px;
+  vertical-align: middle;
+  white-space: nowrap;
+}
+
+#mirroring-fullscreen-video-dropdown {
+  width: auto;
 }

diff --git a/chrome/browser/resources/media_router/elements/route_controls/route_controls.html b/chrome/browser/resources/media_router/elements/route_controls/route_controls.html
index b9ecc9eb..f20cbbc 100644
--- a/chrome/browser/resources/media_router/elements/route_controls/route_controls.html
+++ b/chrome/browser/resources/media_router/elements/route_controls/route_controls.html

@@ -1,3 +1,4 @@
+<link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/av-icons.html">
@@ -7,6 +8,7 @@
   <link rel="import" type="css" href="../../media_router_common.css">
   <link rel="import" type="css" href="route_controls.css">
   <template>
+    <style include="md-select"></style>
     <div id="media-controls">
       <div class="ellipsis" id="route-description"
            title="[[routeDescription_]]">
@@ -81,14 +83,22 @@
             </paper-checkbox>
           </div>
         </div>
-        <div id="media-remoting-enabled-controls"
+        <div id="mirroring-fullscreen-video-controls"
              hidden="[[!routeStatus.mirroringExtraData]]">
-          <paper-checkbox
-              checked="[[!mediaRemotingEnabled_]]"
-              id="always-use-mirroring-checkbox"
-              on-change="onMediaRemotingEnabledChange_">
-            <span>[[i18n('alwaysUseMirroringTitle')]]</span>
-          </paper-checkbox>
+          [[i18n('fullscreenVideosDropdownTitle')]]
+          <span class="md-select-wrapper">
+            <select class="md-select"
+                    id="mirroring-fullscreen-video-dropdown"
+                    on-change="onFullscreenVideoDropdownChange_">
+                <option value="[[FullscreenVideoOption_.REMOTE_SCREEN]]">
+                  [[i18n('fullscreenVideosRemoteScreen')]]
+                </option>
+                <option value="[[FullscreenVideoOption_.BOTH_SCREENS]]">
+                  [[i18n('fullscreenVideosBothScreens')]]
+                </option>
+            </select>
+            <span class="md-select-underline"></span>
+          </span>
         </div>
       </div>
     </div>

diff --git a/chrome/browser/resources/media_router/elements/route_controls/route_controls.js b/chrome/browser/resources/media_router/elements/route_controls/route_controls.js
index d84188e..ab724032 100644
--- a/chrome/browser/resources/media_router/elements/route_controls/route_controls.js
+++ b/chrome/browser/resources/media_router/elements/route_controls/route_controls.js

@@ -12,6 +12,20 @@
 
   properties: {
     /**
+     * Set of possible options for playing fullscreen videos when mirroring.
+     * @private {!Object}
+     */
+    FullscreenVideoOption_: {
+      type: Object,
+      value: {
+        // Play on remote screen only.
+        REMOTE_SCREEN: 'remote_screen',
+        // Play on both remote and local screens.
+        BOTH_SCREENS: 'both_screens'
+      }
+    },
+
+    /**
      * The current time displayed in seconds, before formatting.
      * @private {number}
      */
@@ -371,8 +385,16 @@
     }
     this.hangoutsLocalPresent_ = !!newRouteStatus.hangoutsExtraData &&
         newRouteStatus.hangoutsExtraData.localPresent;
-    this.mediaRemotingEnabled_ = !!newRouteStatus.mirroringExtraData &&
-        newRouteStatus.mirroringExtraData.mediaRemotingEnabled;
+    if (newRouteStatus.mirroringExtraData) {
+      // Manually update the selected value on the
+      // mirroring-fullscreen-video-dropdown dropbox.
+      // TODO(imcheng): Avoid doing this by wrapping the dropbox in a Polymer
+      // template, or introduce <paper-dropdown-menu> to the Polymer library.
+      this.$['mirroring-fullscreen-video-dropdown'].value =
+          newRouteStatus.mirroringExtraData.mediaRemotingEnabled ?
+          this.FullscreenVideoOption_.REMOTE_SCREEN :
+          this.FullscreenVideoOption_.BOTH_SCREENS;
+    }
   },
 
   /**
@@ -446,13 +468,16 @@
   },
 
   /**
-   * Called when the "always use mirroring" box is changed by the user.
-   * @param {!Event} e "always use mirroring" paper-checkbox's change event
+   * Called when the value on the mirroring-fullscreen-video-dropdown dropdown
+   * menu changes.
+   * @param {!Event} e
    * @private
    */
-  onMediaRemotingEnabledChange_: function(e) {
-    this.mediaRemotingEnabled_ = !e.target.checked;
-    media_router.browserApi.setMediaRemotingEnabled(this.mediaRemotingEnabled_);
+  onFullscreenVideoDropdownChange_: function(e) {
+    /** @const */ var dropdownValue =
+        this.$['mirroring-fullscreen-video-dropdown'].value;
+    media_router.browserApi.setMediaRemotingEnabled(
+        dropdownValue == this.FullscreenVideoOption_.REMOTE_SCREEN);
   },
 
   /**

diff --git a/chrome/browser/resources/media_router/media_router.css b/chrome/browser/resources/media_router/media_router.css
index ad517c4..4b3904a 100644
--- a/chrome/browser/resources/media_router/media_router.css
+++ b/chrome/browser/resources/media_router/media_router.css

@@ -3,7 +3,6 @@
  * found in the LICENSE file. */
 
 body {
-  font-family: Roboto;
   font-size: 0.75em;
   margin: 0;
 }

diff --git a/chrome/browser/resources/media_router/media_router_common.css b/chrome/browser/resources/media_router/media_router_common.css
index ee07e9d..3006f99 100644
--- a/chrome/browser/resources/media_router/media_router_common.css
+++ b/chrome/browser/resources/media_router/media_router_common.css

@@ -8,6 +8,9 @@
   --dialog-width: 340px;
   --navigation-icon-button-size: 36px;
   --non-navigation-icon-size: 16px;
+  -webkit-font-smoothing: antialiased;
+  -webkit-tap-highlight-color: transparent;
+  font-family: 'Roboto', 'Noto', sans-serif;
 }
 
 .button {

diff --git a/chrome/browser/signin/chromeos_mirror_account_consistency_browsertest.cc b/chrome/browser/signin/chromeos_mirror_account_consistency_browsertest.cc
index 52bea883..dbdf3ad 100644
--- a/chrome/browser/signin/chromeos_mirror_account_consistency_browsertest.cc
+++ b/chrome/browser/signin/chromeos_mirror_account_consistency_browsertest.cc

@@ -37,6 +37,7 @@
 constexpr char kGaiaUrl[] = "https://accounts.google.com";
 constexpr char kChromeConnectedHeader[] = "X-Chrome-Connected";
 constexpr char kUserEmail[] = "user@gmail.com";
+constexpr char kUserGaiaId[] = "1234567890";
 
 void CheckRequestHeader(net::URLRequest* url_request,
                         const char* header_name,
@@ -95,7 +96,7 @@
 
   ChromeOsMirrorAccountConsistencyTest()
       : LoginManagerTest(false),
-        account_id_(AccountId::FromUserEmail(kUserEmail)) {}
+        account_id_(AccountId::FromUserEmailGaiaId(kUserEmail, kUserGaiaId)) {}
 
   const AccountId account_id_;
 
@@ -105,7 +106,7 @@
 
 IN_PROC_BROWSER_TEST_F(ChromeOsMirrorAccountConsistencyTest,
                        PRE_TestMirrorRequestChromeOsChildAccount) {
-  RegisterUser(account_id_.GetUserEmail());
+  RegisterUser(account_id_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -115,7 +116,7 @@
   // On Chrome OS this is false.
   ASSERT_FALSE(signin::IsAccountConsistencyMirrorEnabled());
   // Child user.
-  LoginUser(account_id_.GetUserEmail());
+  LoginUser(account_id_);
 
   user_manager::User* user = user_manager::UserManager::Get()->GetActiveUser();
   ASSERT_EQ(user, user_manager::UserManager::Get()->GetPrimaryUser());
@@ -144,7 +145,7 @@
 
 IN_PROC_BROWSER_TEST_F(ChromeOsMirrorAccountConsistencyTest,
                        PRE_TestMirrorRequestChromeOsNotChildAccount) {
-  RegisterUser(account_id_.GetUserEmail());
+  RegisterUser(account_id_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -154,7 +155,7 @@
   // On Chrome OS this is false.
   ASSERT_FALSE(signin::IsAccountConsistencyMirrorEnabled());
   // Not a child user.
-  LoginUser(account_id_.GetUserEmail());
+  LoginUser(account_id_);
 
   user_manager::User* user = user_manager::UserManager::Get()->GetActiveUser();
   ASSERT_EQ(user, user_manager::UserManager::Get()->GetPrimaryUser());

diff --git a/chrome/browser/ui/ash/chrome_new_window_client_browsertest.cc b/chrome/browser/ui/ash/chrome_new_window_client_browsertest.cc
index ea52ecf..f41e7bf 100644
--- a/chrome/browser/ui/ash/chrome_new_window_client_browsertest.cc
+++ b/chrome/browser/ui/ash/chrome_new_window_client_browsertest.cc

@@ -17,8 +17,10 @@
 
 namespace {
 
-const char kTestUserName1[] = "test1@test.com";
-const char kTestUserName2[] = "test2@test.com";
+constexpr char kTestUserName1[] = "test1@test.com";
+constexpr char kTestUser1GaiaId[] = "1111111111";
+constexpr char kTestUserName2[] = "test2@test.com";
+constexpr char kTestUser2GaiaId[] = "2222222222";
 
 void CreateAndStartUserSession(const AccountId& account_id) {
   using chromeos::ProfileHelper;
@@ -45,7 +47,8 @@
 // should open a new window.
 IN_PROC_BROWSER_TEST_F(ChromeNewWindowClientBrowserTest,
                        NewWindowForActiveWindowProfileTest) {
-  CreateAndStartUserSession(AccountId::FromUserEmail(kTestUserName1));
+  CreateAndStartUserSession(
+      AccountId::FromUserEmailGaiaId(kTestUserName1, kTestUser1GaiaId));
   Profile* profile1 = ProfileManager::GetActiveUserProfile();
   Browser* browser1 = CreateBrowser(profile1);
   // The newly created window should be created for the current active profile.
@@ -53,7 +56,8 @@
   EXPECT_EQ(GetLastActiveBrowser()->profile(), profile1);
 
   // Login another user and make sure the current active user changes.
-  CreateAndStartUserSession(AccountId::FromUserEmail(kTestUserName2));
+  CreateAndStartUserSession(
+      AccountId::FromUserEmailGaiaId(kTestUserName2, kTestUser2GaiaId));
   Profile* profile2 = ProfileManager::GetActiveUserProfile();
   EXPECT_NE(profile1, profile2);
 
@@ -84,7 +88,8 @@
 }
 
 IN_PROC_BROWSER_TEST_F(ChromeNewWindowClientBrowserTest, IncognitoDisabled) {
-  CreateAndStartUserSession(AccountId::FromUserEmail(kTestUserName1));
+  CreateAndStartUserSession(
+      AccountId::FromUserEmailGaiaId(kTestUserName1, kTestUser2GaiaId));
   Profile* profile = ProfileManager::GetActiveUserProfile();
   EXPECT_EQ(1u, chrome::GetTotalBrowserCount());
 

diff --git a/chrome/browser/ui/ash/session_controller_client_unittest.cc b/chrome/browser/ui/ash/session_controller_client_unittest.cc
index c243c200..966fcf4 100644
--- a/chrome/browser/ui/ash/session_controller_client_unittest.cc
+++ b/chrome/browser/ui/ash/session_controller_client_unittest.cc

@@ -42,7 +42,8 @@
 
 namespace {
 
-const char* kUser = "user@test.com";
+constexpr char kUser[] = "user@test.com";
+constexpr char kUserGaiaId[] = "0123456789";
 
 // Weak ptr to PolicyCertVerifier - object is freed in test destructor once
 // we've ensured the profile has been shut down.
@@ -207,12 +208,11 @@
   }
 
   // Add and log in a user to the session.
-  void UserAddedToSession(std::string user) {
-    const AccountId account_id(AccountId::FromUserEmail(user));
+  void UserAddedToSession(const AccountId& account_id) {
     user_manager()->AddUser(account_id);
     session_manager_.CreateSession(
-        account_id,
-        chromeos::ProfileHelper::GetUserIdHashByUserIdForTesting(user));
+        account_id, chromeos::ProfileHelper::GetUserIdHashByUserIdForTesting(
+                        account_id.GetUserEmail()));
     session_manager_.SetSessionState(SessionState::ACTIVE);
   }
 
@@ -228,7 +228,8 @@
 
   // Adds a regular user with a profile.
   TestingProfile* InitForMultiProfile() {
-    const AccountId account_id(AccountId::FromUserEmail(kUser));
+    const AccountId account_id(
+        AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
     const user_manager::User* user = user_manager()->AddUser(account_id);
 
     // Note that user profiles are created after user login in reality.
@@ -267,7 +268,8 @@
 
 // Make sure that cycling one user does not cause any harm.
 TEST_F(SessionControllerClientTest, CyclingOneUser) {
-  UserAddedToSession("firstuser@test.com");
+  UserAddedToSession(
+      AccountId::FromUserEmailGaiaId("firstuser@test.com", "1111111111"));
 
   EXPECT_EQ("firstuser@test.com", GetActiveUserEmail());
   SessionControllerClient::DoCycleActiveUser(ash::CycleUserDirection::NEXT);
@@ -284,11 +286,16 @@
   client.session_controller_ = session_controller.CreateInterfacePtrAndBind();
   client.Init();
 
-  UserAddedToSession("firstuser@test.com");
-  UserAddedToSession("seconduser@test.com");
-  UserAddedToSession("thirduser@test.com");
-  user_manager()->SwitchActiveUser(
-      AccountId::FromUserEmail("firstuser@test.com"));
+  const AccountId first_user =
+      AccountId::FromUserEmailGaiaId("firstuser@test.com", "1111111111");
+  const AccountId second_user =
+      AccountId::FromUserEmailGaiaId("seconduser@test.com", "2222222222");
+  const AccountId third_user =
+      AccountId::FromUserEmailGaiaId("thirduser@test.com", "3333333333");
+  UserAddedToSession(first_user);
+  UserAddedToSession(second_user);
+  UserAddedToSession(third_user);
+  user_manager()->SwitchActiveUser(first_user);
   SessionControllerClient::FlushForTesting();
 
   // Cycle forward.
@@ -322,12 +329,14 @@
   TestingProfile* user_profile = InitForMultiProfile();
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
-  const AccountId account_id(AccountId::FromUserEmail(kUser));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
   EXPECT_EQ(ash::AddUserSessionPolicy::ERROR_NO_ELIGIBLE_USERS,
             SessionControllerClient::GetAddUserSessionPolicy());
 
-  user_manager()->AddUser(AccountId::FromUserEmail("bb@b.b"));
+  user_manager()->AddUser(
+      AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444"));
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
 
@@ -342,9 +351,11 @@
 TEST_F(SessionControllerClientTest,
        MultiProfileDisallowedByPolicyCertificates) {
   InitForMultiProfile();
-  user_manager()->AddUser(AccountId::FromUserEmail("bb@b.b"));
+  user_manager()->AddUser(
+      AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444"));
 
-  const AccountId account_id(AccountId::FromUserEmail(kUser));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
@@ -361,9 +372,11 @@
 TEST_F(SessionControllerClientTest,
        MultiProfileDisallowedByPrimaryUserCertificatesInMemory) {
   TestingProfile* user_profile = InitForMultiProfile();
-  user_manager()->AddUser(AccountId::FromUserEmail("bb@b.b"));
+  user_manager()->AddUser(
+      AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444"));
 
-  const AccountId account_id(AccountId::FromUserEmail(kUser));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
@@ -397,11 +410,11 @@
 
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
-  AccountId account_id(AccountId::FromUserEmail(kUser));
+  AccountId account_id(AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
   while (user_manager()->GetLoggedInUsers().size() <
          session_manager::kMaximumNumberOfUserSessions) {
-    account_id = AccountId::FromUserEmail("bb@b.b");
+    account_id = AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444");
     user_manager()->AddUser(account_id);
     user_manager()->LoginUser(account_id);
   }
@@ -417,9 +430,10 @@
 
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
-  const AccountId account_id(AccountId::FromUserEmail(kUser));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
-  UserAddedToSession("bb@b.b");
+  UserAddedToSession(AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444"));
   EXPECT_EQ(ash::AddUserSessionPolicy::ERROR_NO_ELIGIBLE_USERS,
             SessionControllerClient::GetAddUserSessionPolicy());
 }
@@ -431,12 +445,14 @@
 
   EXPECT_EQ(ash::AddUserSessionPolicy::ALLOWED,
             SessionControllerClient::GetAddUserSessionPolicy());
-  const AccountId account_id(AccountId::FromUserEmail(kUser));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId(kUser, kUserGaiaId));
   user_manager()->LoginUser(account_id);
   user_profile->GetPrefs()->SetString(
       prefs::kMultiProfileUserBehavior,
       chromeos::MultiProfileUserController::kBehaviorNotAllowed);
-  user_manager()->AddUser(AccountId::FromUserEmail("bb@b.b"));
+  user_manager()->AddUser(
+      AccountId::FromUserEmailGaiaId("bb@b.b", "4444444444"));
   EXPECT_EQ(ash::AddUserSessionPolicy::ERROR_NOT_ALLOWED_PRIMARY_USER,
             SessionControllerClient::GetAddUserSessionPolicy());
 }
@@ -453,11 +469,12 @@
   EXPECT_EQ(0, session_controller.update_user_session_count());
 
   // Simulate login.
-  const AccountId account_id(AccountId::FromUserEmail("user@test.com"));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId("user@test.com", "5555555555"));
   user_manager()->AddUser(account_id);
   session_manager_.CreateSession(
       account_id, chromeos::ProfileHelper::GetUserIdHashByUserIdForTesting(
-                      "user@test.com"));
+                      account_id.GetUserEmail()));
   session_manager_.SetSessionState(SessionState::ACTIVE);
   SessionControllerClient::FlushForTesting();
 
@@ -542,11 +559,12 @@
   SessionControllerClient::FlushForTesting();
 
   // Simulate login.
-  const AccountId account_id(AccountId::FromUserEmail("user@test.com"));
+  const AccountId account_id(
+      AccountId::FromUserEmailGaiaId("user@test.com", "5555555555"));
   const user_manager::User* user = user_manager()->AddUser(account_id);
   session_manager_.CreateSession(
       account_id, chromeos::ProfileHelper::GetUserIdHashByUserIdForTesting(
-                      "user@test.com"));
+                      account_id.GetUserEmail()));
   session_manager_.SetSessionState(SessionState::ACTIVE);
   SessionControllerClient::FlushForTesting();
 

diff --git a/chrome/browser/ui/ash/system_tray_client_browsertest.cc b/chrome/browser/ui/ash/system_tray_client_browsertest.cc
index 51144ba1..38753ea7 100644
--- a/chrome/browser/ui/ash/system_tray_client_browsertest.cc
+++ b/chrome/browser/ui/ash/system_tray_client_browsertest.cc

@@ -167,8 +167,10 @@
   SystemTrayClientClockTest()
       : LoginManagerTest(false /* should_launch_browser */),
         // Use consumer emails to avoid having to fake a policy fetch.
-        account_id1_(AccountId::FromUserEmail("user1@gmail.com")),
-        account_id2_(AccountId::FromUserEmail("user2@gmail.com")) {}
+        account_id1_(
+            AccountId::FromUserEmailGaiaId("user1@gmail.com", "1111111111")),
+        account_id2_(
+            AccountId::FromUserEmailGaiaId("user2@gmail.com", "2222222222")) {}
 
   ~SystemTrayClientClockTest() override = default;
 
@@ -190,8 +192,8 @@
 
 IN_PROC_BROWSER_TEST_F(SystemTrayClientClockTest,
                        PRE_TestMultiProfile24HourClock) {
-  RegisterUser(account_id1_.GetUserEmail());
-  RegisterUser(account_id2_.GetUserEmail());
+  RegisterUser(account_id1_);
+  RegisterUser(account_id2_);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
@@ -205,7 +207,7 @@
   ash::mojom::SystemTrayTestApiAsyncWaiter wait_for(tray_test_api.get());
 
   // Login a user with a 24-hour clock.
-  LoginUser(account_id1_.GetUserEmail());
+  LoginUser(account_id1_);
   SetupUserProfile(account_id1_, true /* use_24_hour_clock */);
   bool is_24_hour = false;
   wait_for.Is24HourClock(&is_24_hour);
@@ -214,7 +216,7 @@
   // Add a user with a 12-hour clock.
   chromeos::UserAddingScreen::Get()->Start();
   content::RunAllPendingInMessageLoop();
-  AddUser(account_id2_.GetUserEmail());
+  AddUser(account_id2_);
   SetupUserProfile(account_id2_, false /* use_24_hour_clock */);
   wait_for.Is24HourClock(&is_24_hour);
   EXPECT_FALSE(is_24_hour);

diff --git a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
index 0f5892d..f709b87 100644
--- a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc

@@ -62,6 +62,15 @@
   html_source->AddLocalizedString(
       "alwaysUseMirroringTitle",
       IDS_MEDIA_ROUTER_ROUTE_DETAILS_ALWAYS_USE_MIRRORING_TITLE);
+  html_source->AddLocalizedString(
+      "fullscreenVideosDropdownTitle",
+      IDS_MEDIA_ROUTER_ROUTE_DETAILS_FULLSCREEN_VIDEOS_DROPDOWN_TITLE);
+  html_source->AddLocalizedString(
+      "fullscreenVideosRemoteScreen",
+      IDS_MEDIA_ROUTER_ROUTE_DETAILS_FULLSCREEN_VIDEOS_REMOTE_SCREEN);
+  html_source->AddLocalizedString(
+      "fullscreenVideosBothScreens",
+      IDS_MEDIA_ROUTER_ROUTE_DETAILS_FULLSCREEN_VIDEOS_BOTH_SCREENS);
 }
 
 void AddIssuesStrings(content::WebUIDataSource* html_source) {

diff --git a/chrome/test/data/webui/media_router/route_controls_tests.js b/chrome/test/data/webui/media_router/route_controls_tests.js
index c681514..f221dd08 100644
--- a/chrome/test/data/webui/media_router/route_controls_tests.js
+++ b/chrome/test/data/webui/media_router/route_controls_tests.js

@@ -273,24 +273,29 @@
       });
 
       test('set media remoting enabled', function(done) {
-        assertElementHidden('media-remoting-enabled-controls');
+        assertElementHidden('mirroring-fullscreen-video-controls');
         let routeStatus = createRouteStatus();
         controls.routeStatus = routeStatus;
-        assertElementHidden('media-remoting-enabled-controls');
+        assertElementHidden('mirroring-fullscreen-video-controls');
 
         routeStatus = createRouteStatus();
         routeStatus.mirroringExtraData = {mediaRemotingEnabled: true};
         controls.routeStatus = routeStatus;
-        assertElementShown('media-remoting-enabled-controls');
-        assertFalse(controls.$$('#always-use-mirroring-checkbox').checked);
+        assertElementShown('mirroring-fullscreen-video-controls');
+        assertEquals(controls.FullscreenVideoOption_.REMOTE_SCREEN,
+            controls.$$('#mirroring-fullscreen-video-dropdown').value);
 
         document.addEventListener('mock-set-media-remoting-enabled',
             function(e) {
+              assertFalse(e.detail.enabled);
               done();
             });
 
-        MockInteractions.tap(controls.$$('#always-use-mirroring-checkbox'));
-        assertTrue(controls.$$('#always-use-mirroring-checkbox').checked);
+        // Simulate changing the dropdown menu value.
+        controls.$$('#mirroring-fullscreen-video-dropdown').value =
+            controls.FullscreenVideoOption_.BOTH_SCREENS;
+        controls.$$('#mirroring-fullscreen-video-dropdown').dispatchEvent(
+            new Event('change'));
       });
 
       test('hangouts local present mode', function(done) {

diff --git a/components/arc/arc_session_impl_unittest.cc b/components/arc/arc_session_impl_unittest.cc
index 93b5515b..d9e7133e 100644
--- a/components/arc/arc_session_impl_unittest.cc
+++ b/components/arc/arc_session_impl_unittest.cc

@@ -27,6 +27,7 @@
 namespace {
 
 constexpr char kFakeGmail[] = "user@gmail.com";
+constexpr char kFakeGmailGaiaId[] = "1234567890";
 
 class FakeDelegate : public ArcSessionImpl::Delegate {
  public:
@@ -127,13 +128,15 @@
     GetSessionManagerClient()->set_arc_available(true);
 
     // Create a user and set it as the primary user.
-    const AccountId account_id = AccountId::FromUserEmail(kFakeGmail);
+    const AccountId account_id =
+        AccountId::FromUserEmailGaiaId(kFakeGmail, kFakeGmailGaiaId);
     const user_manager::User* user = GetUserManager()->AddUser(account_id);
     GetUserManager()->UserLoggedIn(account_id, user->username_hash(), false);
   }
 
   ~ArcSessionImplTest() override {
-    GetUserManager()->RemoveUserFromList(AccountId::FromUserEmail(kFakeGmail));
+    GetUserManager()->RemoveUserFromList(
+        AccountId::FromUserEmailGaiaId(kFakeGmail, kFakeGmailGaiaId));
     chromeos::DBusThreadManager::Shutdown();
   }
 

diff --git a/components/arc/arc_util_unittest.cc b/components/arc/arc_util_unittest.cc
index c739f35..e653428 100644
--- a/components/arc/arc_util_unittest.cc
+++ b/components/arc/arc_util_unittest.cc

@@ -47,7 +47,7 @@
 class FakeUser : public user_manager::User {
  public:
   explicit FakeUser(user_manager::UserType user_type)
-      : User(AccountId::FromUserEmail("user@test.com")),
+      : User(AccountId::FromUserEmailGaiaId("user@test.com", "1234567890")),
         user_type_(user_type) {}
   ~FakeUser() override = default;
 
@@ -210,8 +210,9 @@
   // An ephemeral user is a logged in user but unknown to UserManager when
   // ephemeral policy is set.
   fake_user_manager->SetEphemeralUsersEnabled(true);
-  fake_user_manager->UserLoggedIn(AccountId::FromUserEmail("test@test.com"),
-                                  "test@test.com-hash", false);
+  fake_user_manager->UserLoggedIn(
+      AccountId::FromUserEmailGaiaId("test@test.com", "9876543210"),
+      "test@test.com-hash", false);
   const user_manager::User* ephemeral_user = fake_user_manager->GetActiveUser();
   ASSERT_TRUE(ephemeral_user);
   ASSERT_TRUE(fake_user_manager->IsUserCryptohomeDataEphemeral(

diff --git a/components/user_manager/known_user.cc b/components/user_manager/known_user.cc
index 5e0a156..8763f42 100644
--- a/components/user_manager/known_user.cc
+++ b/components/user_manager/known_user.cc

@@ -526,8 +526,20 @@
 }
 
 // Exported so tests can call this from other components.
-void RemovePrefsForTesting(const AccountId& account_id) {
-  RemovePrefs(account_id);
+void RemoveSetProfileEverInitializedPrefForTesting(
+    const AccountId& account_id) {
+  const base::DictionaryValue* prefs = nullptr;
+  if (!FindPrefs(account_id, &prefs))
+    return;
+
+  if (!prefs->HasKey(kProfileEverInitialized))
+    return;
+
+  std::unique_ptr<base::DictionaryValue> new_prefs(prefs->CreateDeepCopy());
+  if (!new_prefs->RemoveKey(kProfileEverInitialized))
+    return;
+
+  UpdatePrefs(account_id, *new_prefs, true);
 }
 
 void RegisterPrefs(PrefRegistrySimple* registry) {

diff --git a/components/user_manager/known_user.h b/components/user_manager/known_user.h
index 22d9c4bf..3c3473d 100644
--- a/components/user_manager/known_user.h
+++ b/components/user_manager/known_user.h

@@ -159,9 +159,11 @@
 
 // Removes all user preferences associated with |account_id|.
 // Not exported as code should not be calling this outside this component
-// (with the exception of tests, so a test-only API is exposed).
 void RemovePrefs(const AccountId& account_id);
-void USER_MANAGER_EXPORT RemovePrefsForTesting(const AccountId& account_id);
+
+// Clears kProfileEverInitialized for a user.
+void USER_MANAGER_EXPORT
+RemoveSetProfileEverInitializedPrefForTesting(const AccountId& account_id);
 
 // Register known user prefs.
 void USER_MANAGER_EXPORT RegisterPrefs(PrefRegistrySimple* registry);

diff --git a/net/http/http_stream_factory_impl_job_controller_unittest.cc b/net/http/http_stream_factory_impl_job_controller_unittest.cc
index 5553121..df7a00d 100644
--- a/net/http/http_stream_factory_impl_job_controller_unittest.cc
+++ b/net/http/http_stream_factory_impl_job_controller_unittest.cc

@@ -1507,6 +1507,11 @@
 
   EXPECT_TRUE(job_controller_->main_job());
   request_.reset();
+  // Reset task environment back to the default type.
+  // TODO(xunjieli): Remove this temporary workaround once crbug.com/791831 is
+  // fixed.
+  NetTestSuite::SetScopedTaskEnvironment(
+      base::test::ScopedTaskEnvironment::MainThreadType::IO);
 }
 
 // Test that main job is blocked for kMaxDelayTimeForMainJob(3s) if

diff --git a/third_party/WebKit/LayoutTests/fast/harness/results.html b/third_party/WebKit/LayoutTests/fast/harness/results.html
index 5d22946..71188ab 100644
--- a/third_party/WebKit/LayoutTests/fast/harness/results.html
+++ b/third_party/WebKit/LayoutTests/fast/harness/results.html

@@ -272,9 +272,9 @@
 <div id="dashboard">
   <div>
     <span class="fix-width">Query</span>
-    <button id="button_unexpected_fail" onclick="javascript:Query.query('Unexpected failures', Filters.unexpectedFailure, true)">
-      Unexpected Failure
-      <span id="count_unexpected_fail"></span>
+    <button id="button_regressions" onclick="javascript:Query.query('Regressions', Filters.regression, true)">
+      Regressions
+      <span id="count_regressions"></span>
     </button>
     <button onclick="javascript:Query.query('Unexpected passes', Filters.unexpectedPass, true)">
       Unexpected Pass
@@ -400,8 +400,7 @@
         this.resultCounts[node.actualFinal]++;
         action(node, path, this);
       }
-    }
-    else {
+    } else {
       for (let p of node.keys())
         this._helper(node.get(p), path + "/" + p, filter, action);
     }
@@ -416,11 +415,10 @@
 class PathParser {
   constructor(path) {
     this.path = path;
-    let [href, dir, file] = path.match("/(.*)/(.*)");
-    this.dir = dir;
-    this.file = file;
-    let tmp;
-    [tmp, this.basename, this.extension] = file.match(/(.*)\.(\w+)/);
+    let href;
+    [href, this.dir, this.file] = path.match("/(.*/)?(.*)");
+    this.dir = this.dir || "";
+    [, this.basename, this.extension] = this.file.match(/(.*)\.(\w+)/);
     this.testHref = this.testBaseHref() + href.replace(/\/virtual\/[^\/]*/, "");
   }
 
@@ -430,7 +428,7 @@
   }
 
   resultLink(resultName) {
-    return this.dir + "/" + this.basename + resultName;
+    return this.dir + this.basename + resultName;
   }
 
   repaintOverlayLink() {
@@ -485,7 +483,7 @@
     let html = `
     <div class='expect' tabindex='0' data-id='${test.expectId}'>
       <div class='details'></div>${Report.printFlag(test)}
-     ${pathParser.dir}/<a target='test' tabindex='-1' href='${pathParser.testHref}'>${pathParser.file}</a>
+     ${pathParser.dir}<a target='test' tabindex='-1' href='${pathParser.testHref}'>${pathParser.file}</a>
     </div>`;
     traversal.html.push(html);
   },
@@ -541,7 +539,7 @@
     let key = test[key_title];
     let html = ""
       + `${Report.printFlag(test)}`
-      + pathParser.dir + "/"
+      + pathParser.dir
       + "<a target='test' tabindex='-1' href='" + pathParser.testHref + "'>"
       + pathParser.file + "</a>";
     html = "<div class='expect' tabindex='0' data-id='"+ test.expectId +"'><div class='details'></div>" + html + "</div>";
@@ -851,7 +849,7 @@
   unexpectedPass: test => {
     return !Filters.containsPass(test.expectedMap) && Filters.containsPass(test.actualMap);
   },
-  unexpectedFailure: test => {
+  regression: test => {
     if (Filters.containsPass(test.actualMap))
       return false;
     if (test.expectedMap.has("NEEDSMANUALREBASELINE")
@@ -873,7 +871,7 @@
           return false;
         break;
       case "MISSING":
-        return false;
+        break;
       default:
         console.error("Unexpected test result", est.actualMap.keys().next().value);
       }
@@ -903,8 +901,8 @@
     GUI.printSummary(globalResults);
     GUI.initEvents();
     PathParser.initGlobals(results);
-    // Show unexpected failures on startup.
-    document.querySelector("#button_unexpected_fail").click();
+    // Show regressions on startup.
+    document.querySelector("#button_regressions").click();
   },
 
   convertToMap: function(o) {
@@ -1146,7 +1144,7 @@
     let singleLine = "";
     new Traversal(globalResults.tests).traverse(Query.lastReport.filter, (_, path) => {
       let pathParser = new PathParser(path);
-      singleLine += pathParser.dir + "/" + pathParser.file + " ";
+      singleLine += pathParser.dir + pathParser.file + " ";
     });
     let pre = document.createElement("pre");
     pre.setAttribute("style", "overflow: hidden; color: white; height: 1px");
@@ -1174,7 +1172,7 @@
     // Initialize query counts.
     let counts = {
       "count_unexpected_pass": 0,
-      "count_unexpected_fail": 0,
+      "count_regressions": 0,
       "count_testexpectations": 0,
       "count_flaky": 0,
       "count_all": 0,
@@ -1184,13 +1182,17 @@
       counts.count_all++;
       if (Filters.unexpectedPass(test))
         counts.count_unexpected_pass++;
-      if (Filters.unexpectedFailure(test))
-        counts.count_unexpected_fail++;
+      if (Filters.regression(test))
+        counts.count_regressions++;
       if (Filters.notpass(test))
         counts.count_testexpectations++;
       if (Filters.flaky(test))
         counts.count_flaky++;
     });
+    console.assert(
+        counts.count_regressions == fullResults.num_regressions,
+        "Numbers of regressions mismatch: in fullResult:" + fullResults.num_regressions +
+        " filtered:" + counts.count_regressions);
     for (let p in counts)
       document.querySelector("#" + p).innerText = counts[p];
 

diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index d917bde..998281d 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp

@@ -6250,13 +6250,9 @@
 
 void Document::EnforceSandboxFlags(SandboxFlags mask) {
   scoped_refptr<SecurityOrigin> stand_in_origin = GetSecurityOrigin();
-  ApplySandboxFlags(mask);
-  // Send a notification if the origin has been updated.
-  if (stand_in_origin && !stand_in_origin->IsUnique() &&
-      GetSecurityOrigin()->IsUnique()) {
-    GetSecurityOrigin()->SetUniqueOriginIsPotentiallyTrustworthy(
-        stand_in_origin->IsPotentiallyTrustworthy());
-  }
+  bool is_potentially_trustworthy =
+      stand_in_origin && stand_in_origin->IsPotentiallyTrustworthy();
+  ApplySandboxFlags(mask, is_potentially_trustworthy);
 }
 
 void Document::UpdateSecurityOrigin(scoped_refptr<SecurityOrigin> origin) {

diff --git a/third_party/WebKit/Source/core/dom/SecurityContext.cpp b/third_party/WebKit/Source/core/dom/SecurityContext.cpp
index 7816b2bb6..f59b4c3 100644
--- a/third_party/WebKit/Source/core/dom/SecurityContext.cpp
+++ b/third_party/WebKit/Source/core/dom/SecurityContext.cpp

@@ -61,12 +61,17 @@
   ApplySandboxFlags(mask);
 }
 
-void SecurityContext::ApplySandboxFlags(SandboxFlags mask) {
+void SecurityContext::ApplySandboxFlags(SandboxFlags mask,
+                                        bool is_potentially_trustworthy) {
   sandbox_flags_ |= mask;
 
   if (IsSandboxed(kSandboxOrigin) && GetSecurityOrigin() &&
       !GetSecurityOrigin()->IsUnique()) {
-    SetSecurityOrigin(SecurityOrigin::CreateUnique());
+    scoped_refptr<SecurityOrigin> security_origin =
+        SecurityOrigin::CreateUnique();
+    security_origin->SetUniqueOriginIsPotentiallyTrustworthy(
+        is_potentially_trustworthy);
+    SetSecurityOrigin(std::move(security_origin));
     DidUpdateSecurityOrigin();
   }
 }

diff --git a/third_party/WebKit/Source/core/dom/SecurityContext.h b/third_party/WebKit/Source/core/dom/SecurityContext.h
index e9b7e12a..d6febff 100644
--- a/third_party/WebKit/Source/core/dom/SecurityContext.h
+++ b/third_party/WebKit/Source/core/dom/SecurityContext.h

@@ -102,7 +102,10 @@
                                const FeaturePolicy* parent_feature_policy);
   void UpdateFeaturePolicyOrigin();
 
-  void ApplySandboxFlags(SandboxFlags mask);
+  // Apply the sandbox flag, and also maybe update the security origin
+  // to the newly created unique one with |is_potentially_trustworthy|.
+  void ApplySandboxFlags(SandboxFlags mask,
+                         bool is_potentially_trustworthy = false);
 
  protected:
   SecurityContext();

diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index b908abf..abfe457 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml

@@ -31661,6 +31661,9 @@
   <int value="0" label="None"/>
   <int value="1" label="Minimal"/>
   <int value="2" label="All"/>
+  <int value="3" label="Browser"/>
+  <int value="4" label="Gpu"/>
+  <int value="5" label="Renderer Sampling"/>
 </enum>
 
 <enum name="OutOfProcessHeapProfilingProcessType">

diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index ddc42c84..b2811b30 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml

@@ -55929,6 +55929,23 @@
   </summary>
 </histogram>
 
+<histogram name="OutOfProcessHeapProfiling.RecordTrace.Success"
+    enum="BooleanSuccess">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The metric is emitted each time Chrome attempts to record a memory-infra
+    trace to upload an out-of-process heap-profiling memory dump.
+  </summary>
+</histogram>
+
+<histogram name="OutOfProcessHeapProfiling.UploadTrace.Size" units="bytes">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The metric is emitted each time Chrome uploads a trace. It reflects the
+    uncompressed size of the trace.
+  </summary>
+</histogram>
+
 <histogram name="Overscroll.Cancelled" enum="NavigationDirection">
   <obsolete>
     Deprecated as of Chrome 59 in favour of Overscroll.Cancelled3.