Show progress bar as soon as update state changed to UPDATE_STATUS_UPDATE_AVAILABLE

chrome/browser/chromeos/login/views_update_screen_actor.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_VIEWS_UPDATE_SCREEN_ACTOR_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_VIEWS_UPDATE_SCREEN_ACTOR_H_
 #pragma once
 
 #include "chrome/browser/chromeos/login/update_screen_actor.h"
 #include "chrome/browser/chromeos/login/update_view.h"
 #include "chrome/browser/chromeos/login/view_screen.h"
 
 namespace chromeos {
 
 class ViewsUpdateScreenActor : public DefaultViewScreen<UpdateView>,
                                public UpdateScreenActor {
  public:
   explicit ViewsUpdateScreenActor(ViewScreenDelegate* delegate);
   virtual ~ViewsUpdateScreenActor() {}
 
   virtual void PrepareToShow();
   virtual void Show();
   virtual void Hide();
   virtual void ShowManualRebootInfo();
   virtual void SetProgress(int progress);
   virtual void ShowCurtain(bool enable);
+  virtual void ShowPreparingUpdatesInfo(bool visible);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ViewsUpdateScreenActor);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_VIEWS_UPDATE_SCREEN_ACTOR_H_