Three dot menu is shown now on WebView start screen.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

 // Copyright (c) 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/chromeos/login/signin_screen_handler.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/shell.h"
@@ skipping 341 matching lines @@
                IDS_LOGIN_POD_MENU_REMOVE_ITEM_ACCESSIBLE_NAME);
   builder->Add("passwordFieldAccessibleName",
                IDS_LOGIN_POD_PASSWORD_FIELD_ACCESSIBLE_NAME);
   builder->Add("signedIn", IDS_SCREEN_LOCK_ACTIVE_USER);
   builder->Add("signinButton", IDS_LOGIN_BUTTON);
   builder->Add("launchAppButton", IDS_LAUNCH_APP_BUTTON);
   builder->Add("restart", IDS_RESTART_BUTTON);
   builder->Add("shutDown", IDS_SHUTDOWN_BUTTON);
   builder->Add("addUser", IDS_ADD_USER_BUTTON);
   builder->Add("browseAsGuest", IDS_GO_INCOGNITO_BUTTON);
+  builder->Add("addSupervisedUser", IDS_CREATE_SUPERVISED_USER_MENU_LABEL);
   builder->Add("cancel", IDS_CANCEL);
   builder->Add("signOutUser", IDS_SCREEN_LOCK_SIGN_OUT);
   builder->Add("offlineLogin", IDS_OFFLINE_LOGIN_HTML);
   builder->Add("ownerUserPattern", IDS_LOGIN_POD_OWNER_USER);
   builder->Add("removeUser", IDS_LOGIN_POD_REMOVE_USER);
   builder->Add("errorTpmFailureTitle", IDS_LOGIN_ERROR_TPM_FAILURE_TITLE);
   builder->Add("errorTpmFailureReboot", IDS_LOGIN_ERROR_TPM_FAILURE_REBOOT);
   builder->Add("errorTpmFailureRebootButton",
                IDS_LOGIN_ERROR_TPM_FAILURE_REBOOT_BUTTON);
 
@@ skipping 997 matching lines @@
   return gaia_screen_handler_->frame_error();
 }
 
 void SigninScreenHandler::OnCapsLockChanged(bool enabled) {
   caps_lock_enabled_ = enabled;
   if (page_is_ready())
     CallJS("login.AccountPickerScreen.setCapsLockState", caps_lock_enabled_);
 }
 
 }  // namespace chromeos