ChromeOS: Implement Update screen of material design OOBE.

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

 // Copyright (c) 2012 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/update_screen_handler.h"
 
 #include <memory>
 
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/screens/update_model.h"
@@ skipping 35 matching lines @@
                IDS_DOWNLOADING_TIME_LEFT_STATUS_MINUTES);
   builder->Add("downloadingTimeLeftSmall", IDS_DOWNLOADING_TIME_LEFT_SMALL);
 
 #if !defined(OFFICIAL_BUILD)
   builder->Add("cancelUpdateHint", IDS_UPDATE_CANCEL);
   builder->Add("cancelledUpdateMessage", IDS_UPDATE_CANCELLED);
 #else
   builder->Add("cancelUpdateHint", IDS_EMPTY_STRING);
   builder->Add("cancelledUpdateMessage", IDS_EMPTY_STRING);
 #endif
+
+  // For Material Design OOBE
+  builder->Add("updatingScreenTitle", IDS_UPDATING_SCREEN_TITLE);
 }
 
 void UpdateScreenHandler::Initialize() {
   if (show_on_init_) {
     Show();
     show_on_init_ = false;
   }
 }
 
 void UpdateScreenHandler::PrepareToShow() {
@@ skipping 14 matching lines @@
   model_ = &model;
   BaseScreenHandler::SetBaseScreen(model_);
 }
 
 void UpdateScreenHandler::Unbind() {
   model_ = nullptr;
   BaseScreenHandler::SetBaseScreen(nullptr);
 }
 
 }  // namespace chromeos