MediaStream audio: Refactor 3 separate "glue" implementations into one.

content/renderer/media/webrtc_local_audio_track.h

-// Copyright 2013 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_WEBRTC_LOCAL_AUDIO_TRACK_H_
-#define CONTENT_RENDERER_MEDIA_WEBRTC_LOCAL_AUDIO_TRACK_H_
-
-#include <list>
-#include <string>
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/thread_checker.h"
-#include "content/renderer/media/media_stream_audio_track.h"
-#include "content/renderer/media/tagged_list.h"
-#include "content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h"
-#include "media/base/audio_parameters.h"
-
-namespace media {
-class AudioBus;
-}
-
-namespace content {
-
-class MediaStreamAudioLevelCalculator;
-class MediaStreamAudioProcessor;
-class MediaStreamAudioSink;
-class MediaStreamAudioSinkOwner;
-class MediaStreamAudioTrackSink;
-
-// A WebRtcLocalAudioTrack manages thread-safe connects/disconnects to sinks,
-// and the delivery of audio data from the source to the sinks.
-class CONTENT_EXPORT WebRtcLocalAudioTrack
-    : NON_EXPORTED_BASE(public MediaStreamAudioTrack) {
- public:
-  explicit WebRtcLocalAudioTrack(
-      scoped_refptr<WebRtcLocalAudioTrackAdapter> adapter);
-
-  ~WebRtcLocalAudioTrack() override;
-
-  // Add a sink to the track. This function will trigger a OnSetFormat()
-  // call on the |sink|.
-  // Called on the main render thread.
-  void AddSink(MediaStreamAudioSink* sink) override;
-
-  // Remove a sink from the track.
-  // Called on the main render thread.
-  void RemoveSink(MediaStreamAudioSink* sink) override;
-
-  // Overrides for MediaStreamTrack.
-  void SetEnabled(bool enabled) override;
-  webrtc::AudioTrackInterface* GetAudioAdapter() override;
-  media::AudioParameters GetOutputFormat() const override;
-
-  // Method called by the capturer to deliver the capture data.
-  // Called on the capture audio thread.
-  void Capture(const media::AudioBus& audio_bus,
-               base::TimeTicks estimated_capture_time);
-
-  // Method called by the capturer to set the audio parameters used by source
-  // of the capture data..
-  // Called on the capture audio thread.
-  void OnSetFormat(const media::AudioParameters& params);
-
-  // Called by the capturer before the audio data flow begins to set the object
-  // that provides shared access to the current audio signal level.
-  void SetLevel(scoped_refptr<MediaStreamAudioLevelCalculator::Level> level);
-
-  // Called by the capturer before the audio data flow begins to provide a
-  // reference to the audio processor so that the track can query stats from it.
-  void SetAudioProcessor(scoped_refptr<MediaStreamAudioProcessor> processor);
-
- private:
-  typedef TaggedList<MediaStreamAudioTrackSink> SinkList;
-
-  // MediaStreamAudioTrack override.
-  void OnStop() final;
-
-  // All usage of libjingle is through this adapter. The adapter holds
-  // a pointer to this object, but no reference.
-  const scoped_refptr<WebRtcLocalAudioTrackAdapter> adapter_;
-
-  // A tagged list of sinks that the audio data is fed to. Tags
-  // indicate tracks that need to be notified that the audio format
-  // has changed.
-  SinkList sinks_;
-
-  // Tests that methods are called on libjingle's signaling thread.
-  base::ThreadChecker signal_thread_checker_;
-
-  // Used to DCHECK that some methods are called on the capture audio thread.
-  base::ThreadChecker capture_thread_checker_;
-
-  // Protects |params_| and |sinks_|.
-  mutable base::Lock lock_;
-
-  // Audio parameters of the audio capture stream.
-  media::AudioParameters audio_parameters_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebRtcLocalAudioTrack);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_WEBRTC_LOCAL_AUDIO_TRACK_H_