Remove #pragma once from content

content/renderer/media/scoped_loop_observer.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 CONTENT_RENDERER_MEDIA_SCOPED_LOOP_OBSERVER_H_
 #define CONTENT_RENDERER_MEDIA_SCOPED_LOOP_OBSERVER_H_
-#pragma once
 
 #include "base/memory/ref_counted.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 
 namespace base {
 class WaitableEvent;
 }
 
 // A common base class for AudioDevice and AudioInputDevice that manages
@@ skipping 19 matching lines @@
   void ObserveLoopDestruction(bool enable, base::WaitableEvent* done);
 
   // A pointer to the message loop's proxy. In case the loop gets destroyed
   // before this object goes out of scope, PostTask etc will fail but not crash.
   scoped_refptr<base::MessageLoopProxy> loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedLoopObserver);
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_SCOPED_LOOP_OBSERVER_H_