Split audio mixer into interface and implementation.

webrtc/modules/audio_mixer/audio_source_with_mix_status.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_
 #define WEBRTC_MODULES_AUDIO_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_
 
-#include "webrtc/modules/audio_mixer/audio_mixer.h"
+#include "webrtc/api/audio/audio_mixer.h"
 
 namespace webrtc {
 
 // A class that holds a mixer participant and its mixing status.
 class AudioSourceWithMixStatus {
  public:
   explicit AudioSourceWithMixStatus(AudioMixer::Source* audio_source);
   ~AudioSourceWithMixStatus();
 
   AudioSourceWithMixStatus(const AudioSourceWithMixStatus&) = default;
@@ skipping 11 matching lines @@
   AudioMixer::Source* audio_source() const;
 
  private:
   AudioMixer::Source* audio_source_ = nullptr;
   bool is_mixed_ = false;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_