Enable Dice for ephemeral Guest profiles.

Account Consistency Mode Manager is enabled for ephemeral Guest
profiles.

Please see go/ephemeral-guest-profiles for more context.

Bug: 1125474
Change-Id: Id7ae0a844e6d582ad70ad12430af107048f40290
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574747Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834280}

chrome/browser/profiles/profile_manager.cc

@@ -1898,7 +1898,8 @@ void ProfileManager::AddProfileToStorage(Profile* profile) {
 
 void ProfileManager::SetNonPersonalProfilePrefs(Profile* profile) {
   PrefService* prefs = profile->GetPrefs();
-  prefs->SetBoolean(prefs::kSigninAllowed, false);
+  if (!profile->IsEphemeralGuestProfile())
+    prefs->SetBoolean(prefs::kSigninAllowed, false);
   prefs->SetBoolean(bookmarks::prefs::kEditBookmarksEnabled, false);
   prefs->SetBoolean(bookmarks::prefs::kShowBookmarkBar, false);
   prefs->ClearPref(DefaultSearchManager::kDefaultSearchProviderDataPrefName);

chrome/browser/signin/account_consistency_mode_manager.cc

@@ -168,7 +168,7 @@ bool AccountConsistencyModeManager::ShouldBuildServiceForProfile(
   // causes crashes if the AccountConsistencyModeManager is instantiated. See
   // https://crbug.com/940026
   return profile->IsRegularProfile() && !profile->IsGuestSession() &&
-         !profile->IsEphemeralGuestProfile() && !profile->IsSystemProfile();
+         !profile->IsSystemProfile();
 }
 
 AccountConsistencyMethod

chrome/browser/signin/account_consistency_mode_manager_unittest.cc

@@ -172,7 +172,8 @@ TEST(AccountConsistencyModeManagerTest, NewProfile) {
       AccountConsistencyModeManager::IsDiceMigrationCompleted(profile.get()));
 }
 
-TEST(AccountConsistencyModeManagerTest, DiceOnlyForRegularProfile) {
+TEST(AccountConsistencyModeManagerTest,
+     DiceOnlyForRegularAndEphemeralGuestProfile) {
   content::BrowserTaskEnvironment task_environment;
 
   {
@@ -209,8 +210,12 @@ TEST(AccountConsistencyModeManagerTest, DiceOnlyForRegularProfile) {
         otr_profile));
   }
 
+  // OTR Guest profile.
   {
-    // Guest profile.
+    base::test::ScopedFeatureList scoped_feature_list;
+    TestingProfile::SetScopedFeatureListForEphemeralGuestProfiles(
+        scoped_feature_list, false);
+
     TestingProfile::Builder profile_builder;
     profile_builder.SetGuestSession();
     std::unique_ptr<Profile> profile = profile_builder.Build();
@@ -224,6 +229,25 @@ TEST(AccountConsistencyModeManagerTest, DiceOnlyForRegularProfile) {
         profile.get()));
   }
 
+  // Ephemeral Guest profile.
+  {
+    base::test::ScopedFeatureList scoped_feature_list;
+    if (TestingProfile::SetScopedFeatureListForEphemeralGuestProfiles(
+            scoped_feature_list, true)) {
+      TestingProfile::Builder profile_builder;
+      profile_builder.SetGuestSession();
+      std::unique_ptr<Profile> profile = profile_builder.Build();
+      ASSERT_TRUE(profile->IsEphemeralGuestProfile());
+      EXPECT_TRUE(AccountConsistencyModeManager::IsDiceEnabledForProfile(
+          profile.get()));
+      EXPECT_EQ(
+          signin::AccountConsistencyMethod::kDice,
+          AccountConsistencyModeManager::GetMethodForProfile(profile.get()));
+      EXPECT_TRUE(AccountConsistencyModeManager::ShouldBuildServiceForProfile(
+          profile.get()));
+    }
+  }
+
   {
     // Legacy supervised profile.
     TestingProfile::Builder profile_builder;