Three dot menu is shown now on WebView start screen.

chrome/browser/ui/webui/signin/user_manager_screen_handler.cc

Index: chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
diff --git a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
index bc11d4dc4ea80081c79af33e33e5462411c75bd5..25e94a244509a5bb9c24b9b9420a64c84e78f568 100644
--- a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
+++ b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
@@ -620,6 +620,8 @@ void UserManagerScreenHandler::GetLocalizedValues(
       l10n_util::GetStringUTF16(IDS_GO_INCOGNITO_BUTTON));
   localized_strings->SetString("signOutUser",
       l10n_util::GetStringUTF16(IDS_SCREEN_LOCK_SIGN_OUT));
+  localized_strings->SetString("addSupervisedUser",
+      l10n_util::GetStringUTF16(IDS_CREATE_SUPERVISED_USER_MENU_LABEL));
 
   // For AccountPickerScreen.
   localized_strings->SetString("screenType", "login-add-user");