media: Cleanup class/struct forward declarations

media/audio/fake_audio_input_stream.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.
 //
 // A fake implementation of AudioInputStream, useful for testing purpose.
 
 #ifndef MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_
 #define MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/fake_audio_worker.h"
 #include "media/base/audio_parameters.h"
 
 namespace media {
 
 class AudioBus;
 class AudioManagerBase;
-class SimpleSource;
 
 // This class acts as a fake audio input stream. The default is to generate a
 // beeping sound unless --use-file-for-fake-audio-capture=<file> is specified,
 // in which case the indicated .wav file will be read and played into the
 // stream.
 class MEDIA_EXPORT FakeAudioInputStream
     : public AudioInputStream {
  public:
   static AudioInputStream* MakeFakeStream(
       AudioManagerBase* manager, const AudioParameters& params);
@@ skipping 36 matching lines @@
 
   std::unique_ptr<AudioOutputStream::AudioSourceCallback> audio_source_;
   std::unique_ptr<media::AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_