Make audio build on the Mac OS X 10.7

audio/mac/audio_low_latency_output_mac.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.
 //
 // Implementation notes:
 //
 // - It is recommended to first acquire the native sample rate of the default
 //   output device and then use the same rate when creating this object.
 //   Use AUAudioOutputStream::HardwareSampleRate() to retrieve the sample rate.
 // - Calling Close() also leads to self destruction.
 // - The latency consists of two parts:
 //   1) Hardware latency, which includes Audio Unit latency, audio device
 //      latency;
 //   2) The delay between the moment getting the callback and the scheduled time
 //      stamp that tells when the data is going to be played out.
 //
 #ifndef MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_OUTPUT_MAC_H_
 #define MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_OUTPUT_MAC_H_
 
 #include <AudioUnit/AudioUnit.h>
+#include <CoreAudio/CoreAudio.h>
 
 #include "base/compiler_specific.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
 namespace media {
 
 class AudioManagerMac;
 
 // Implementation of AudioOuputStream for Mac OS X using the
@@ skipping 66 matching lines @@
 
   // The flag used to stop the streaming.
   bool stopped_;
 
   DISALLOW_COPY_AND_ASSIGN(AUAudioOutputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_OUTPUT_MAC_H_