Remove #pragma once from ash

ash/system/tray/tray_item_more.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_TRAY_ITEM_MORE_H_
 #define ASH_SYSTEM_TRAY_TRAY_ITEM_MORE_H_
-#pragma once
 
 #include "ash/system/tray/tray_views.h"
 #include "ui/views/view.h"
 
 namespace views {
 class ImageView;
 class Label;
 class View;
 }
 
@@ skipping 34 matching lines @@
   views::ImageView* more_;
   string16 accessible_name_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayItemMore);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_TRAY_ITEM_MORE_H_