ash: Refresh the tray items, instead of recreating them, when login status changes.

ash/system/user/tray_user.h

 // 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.
 
 #ifndef ASH_SYSTEM_USER_TRAY_USER_H_
 #define ASH_SYSTEM_USER_TRAY_USER_H_
 #pragma once
 
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/system/user/user_observer.h"
@@ skipping 17 matching lines @@
   virtual ~TrayUser();
 
  private:
   // Overridden from SystemTrayItem
   virtual views::View* CreateTrayView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateDetailedView(user::LoginStatus status) OVERRIDE;
   virtual void DestroyTrayView() OVERRIDE;
   virtual void DestroyDefaultView() OVERRIDE;
   virtual void DestroyDetailedView() OVERRIDE;
+  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) OVERRIDE;
 
   // Overridden from UserObserver.
   virtual void OnUserUpdate() OVERRIDE;
 
   scoped_ptr<tray::UserView> user_;
   scoped_ptr<tray::RoundedImageView> avatar_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayUser);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_USER_TRAY_USER_H_