Remove #pragma once from ash

ash/shell/launcher_delegate_impl.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_LAUNCHER_DELEGATE_IMPL_H_
 #define ASH_SHELL_LAUNCHER_DELEGATE_IMPL_H_
-#pragma once
 
 #include "ash/launcher/launcher_delegate.h"
 #include "base/compiler_specific.h"
 
 namespace aura {
 class Window;
 }
 
 namespace ash {
 namespace shell {
@@ skipping 24 matching lines @@
   // Used to update Launcher. Owned by main.
   WindowWatcher* watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(LauncherDelegateImpl);
 };
 
 }  // namespace shell
 }  // namespace ash
 
 #endif  // ASH_SHELL_LAUNCHER_DELEGATE_IMPL_H_