[iOS] Add flag to switch between sign-in notification infobar titles.

This patch gives us the ability to switch between infobar titles, either
with "Sign in as [fullname]" or "Sign in to Chrome", depending on final
UX decisions.

Bug: 1145592
Change-Id: Ifba41e4aa025ec51d80e76ec79015ace375be103
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2526061
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825317}

chrome/browser/flag-metadata.json

@@ -4677,6 +4677,11 @@
     // wallet-service-use-sandbox on Android.
     "expiry_milestone": -1
   },
+  {
+    "name": "use-username-for-signin-notification-infobar-title",
+    "owners": [ "fernandex", "chrome-signin-team" ],
+    "expiry_milestone": 96
+  },
   {
     "name": "use-wallpaper-staging-url",
     "owners": [ "cros-customization@google.com", "hsuregan", "khorimoto" ],

components/signin/ios/browser/features.cc

@@ -19,4 +19,8 @@ const base::Feature kRestoreGaiaCookiesIfDeleted{
 const char kDelayThresholdMinutesToUpdateGaiaCookie[] =
     "minutes-delay-to-restore-gaia-cookies-if-deleted";
 
+const base::Feature kSigninNotificationInfobarUsernameInTitle{
+    "SigninNotificationInfobarUsernameInTitle",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace signin

components/signin/ios/browser/features.h

@@ -22,6 +22,9 @@ extern const base::Feature kRestoreGaiaCookiesIfDeleted;
 // for the existence of Gaia cookies for google.com.
 extern const char kDelayThresholdMinutesToUpdateGaiaCookie[];
 
+// Feature controlling whether to use full username in sign-in notifications.
+extern const base::Feature kSigninNotificationInfobarUsernameInTitle;
+
 }  // namespace signin
 
 #endif  // COMPONENTS_SIGNIN_IOS_BROWSER_FEATURES_H_

ios/chrome/browser/flags/about_flags.mm

@@ -604,6 +604,11 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kRestoreGaiaCookiesIfDeletedDescription,
      flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(signin::kRestoreGaiaCookiesIfDeleted)},
+    {"use-username-for-signin-notification-infobar-title",
+     flag_descriptions::kSigninNotificationInfobarUsernameInTitleName,
+     flag_descriptions::kSigninNotificationInfobarUsernameInTitleDescription,
+     flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(signin::kSigninNotificationInfobarUsernameInTitle)},
     {"minutes-delay-to-restore-gaia-cookies-if-deleted",
      flag_descriptions::kDelayThresholdMinutesToUpdateGaiaCookieName,
      flag_descriptions::kDelayThresholdMinutesToUpdateGaiaCookieDescription,

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -271,6 +271,12 @@ const char kInfobarUIRebootOnlyiOS13Name[] = "Infobar UI Reboot iOS13";
 const char kInfobarUIRebootOnlyiOS13Description[] =
     "When enabled, Infobar will use the new UI only on iOS13";
 
+const char kSigninNotificationInfobarUsernameInTitleName[] =
+    "Sign-in notification infobar title";
+const char kSigninNotificationInfobarUsernameInTitleDescription[] =
+    "When enabled, uses the authenticated user's full name in the infobar "
+    "title.";
+
 const char kInProductHelpDemoModeName[] = "In-Product Help Demo Mode";
 const char kInProductHelpDemoModeDescription[] =
     "When enabled, in-product help promotions occur exactly once per cold "

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -86,6 +86,11 @@ extern const char kAutofillUseRendererIDsDescription[];
 extern const char kLogBreadcrumbsName[];
 extern const char kLogBreadcrumbsDescription[];
 
+// Title and description for the flag that controls the sign-in notification
+// infobar title.
+extern const char kSigninNotificationInfobarUsernameInTitleName[];
+extern const char kSigninNotificationInfobarUsernameInTitleDescription[];
+
 // Title and description for the flag that controls synthetic crash reports
 // generation for Unexplained Termination Events.
 extern const char kSyntheticCrashReportsForUteName[];