Remove #pragma once from ash

ash/system/locale/tray_locale.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_LOCALE_TRAY_LOCALE_H_
 #define ASH_SYSTEM_LOCALE_TRAY_LOCALE_H_
-#pragma once
 
 #include <string>
 
 #include "ash/system/locale/locale_observer.h"
 #include "ash/system/tray/system_tray_item.h"
 
 namespace ash {
 namespace internal {
 
 namespace tray {
@@ skipping 24 matching lines @@
   std::string from_locale_;
   std::string to_locale_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayLocale);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_LOCALE_TRAY_LOCALE_H_