Remove #pragma once from content

content/common/media/audio_stream_state.h

 // Copyright (c) 2011 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_COMMON_MEDIA_AUDIO_STREAM_STATE_H_
 #define CONTENT_COMMON_MEDIA_AUDIO_STREAM_STATE_H_
-#pragma once
 
 // Current status of the audio output stream in the browser process. Browser
 // sends information about the current playback state and error to the
 // renderer process using this type.
 enum AudioStreamState {
   kAudioStreamPlaying,
   kAudioStreamPaused,
   kAudioStreamError
 };
 
 #endif  // CONTENT_COMMON_MEDIA_AUDIO_STREAM_STATE_H_