Three dot menu is shown now on WebView start screen.

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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/signin/user_manager_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/value_conversions.h"
@@ skipping 602 matching lines @@
       l10n_util::GetStringUTF16(IDS_SCREEN_LOCK_ACTIVE_USER));
   localized_strings->SetString("signinButton",
       l10n_util::GetStringUTF16(IDS_LOGIN_BUTTON));
   localized_strings->SetString("addUser",
       l10n_util::GetStringUTF16(IDS_ADD_USER_BUTTON));
   localized_strings->SetString("cancel", l10n_util::GetStringUTF16(IDS_CANCEL));
   localized_strings->SetString("browseAsGuest",
       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");
   localized_strings->SetString("highlightStrength", "normal");
   localized_strings->SetString("title",
       l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
   localized_strings->SetString("passwordHint",
       l10n_util::GetStringUTF16(IDS_LOGIN_POD_EMPTY_PASSWORD_TEXT));
   localized_strings->SetString("signingIn",
       l10n_util::GetStringUTF16(IDS_LOGIN_POD_SIGNING_IN));
@@ skipping 200 matching lines @@
     Profile* profile, Profile::CreateStatus profile_create_status) {
   Browser* browser = chrome::FindAnyBrowser(profile, false, desktop_type_);
   if (browser && browser->window()) {
     OnBrowserWindowReady(browser);
   } else {
     registrar_.Add(this,
                    chrome::NOTIFICATION_BROWSER_WINDOW_READY,
                    content::NotificationService::AllSources());
   }
 }