Remove #pragma once from ash

ash/test/test_launcher_delegate.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_TEST_TEST_LAUNCHER_DELEGATE_H_
 #define ASH_TEST_TEST_LAUNCHER_DELEGATE_H_
-#pragma once
 
 #include <map>
 #include <set>
 
 #include "ash/launcher/launcher_delegate.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/window_observer.h"
 
 namespace ash {
 
@@ skipping 45 matching lines @@
   // Parent windows we are watching.
   ObservedWindows observed_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(TestLauncherDelegate);
 };
 
 }  // namespace test
 }  // namespace ash
 
 #endif  // ASH_TEST_TEST_LAUNCHER_DELEGATE