Remove scoped_ptr for system tray views

ash/system/tray_update.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_TRAY_UPDATE_H_
 #define ASH_SYSTEM_TRAY_UPDATE_H_
 #pragma once
 
 #include "ash/system/tray/tray_image_item.h"
 
@@ skipping 20 matching lines @@
 
  private:
   // Overridden from TrayImageItem.
   virtual bool GetInitialVisibility() OVERRIDE;
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual void DestroyDefaultView() OVERRIDE;
 
   // Overridden from UpdateObserver.
   virtual void OnUpdateRecommended() OVERRIDE;
 
-  scoped_ptr<views::View> default_;
-
   DISALLOW_COPY_AND_ASSIGN(TrayUpdate);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_UPDATE_H_