Remove #pragma once from ash

ash/shell/toplevel_window.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_SHELL_TOPLEVEL_WINDOW_H_
 #define ASH_SHELL_TOPLEVEL_WINDOW_H_
-#pragma once
 
 #include "ui/views/widget/widget_delegate.h"
 
 namespace ash {
 namespace shell {
 
 class ToplevelWindow : public views::WidgetDelegateView {
  public:
   struct CreateParams {
     CreateParams();
@@ skipping 19 matching lines @@
 
   const CreateParams params_;
 
   DISALLOW_COPY_AND_ASSIGN(ToplevelWindow);
 };
 
 }  // namespace shell
 }  // namespace ash
 
 #endif  // ASH_SHELL_TOPLEVEL_WINDOW_H_