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

content/renderer/media/media_stream_audio_sink_owner.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_MEDIA_STREAM_AUDIO_SINK_OWNER_H_
-#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_SINK_OWNER_H_
-
-#include <vector>
-
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "content/renderer/media/media_stream_audio_track_sink.h"
-
-namespace content {
-
-class MediaStreamAudioSink;
-
-// Reference counted holder of MediaStreamAudioSink sinks.
-class MediaStreamAudioSinkOwner : public MediaStreamAudioTrackSink {
- public:
-  explicit MediaStreamAudioSinkOwner(MediaStreamAudioSink* sink);
-
-  // MediaStreamAudioTrackSink implementation.
-  void OnData(const media::AudioBus& audio_bus,
-              base::TimeTicks estimated_capture_time) override;
-  void OnSetFormat(const media::AudioParameters& params) override;
-  void OnReadyStateChanged(
-      blink::WebMediaStreamSource::ReadyState state) override;
-  void Reset() override;
-  bool IsEqual(const MediaStreamAudioSink* other) const override;
-
- protected:
-  ~MediaStreamAudioSinkOwner() override {}
-
- private:
-  mutable base::Lock lock_;
-
-  // Raw pointer to the delegate, the client need to call Reset() to set the
-  // pointer to NULL before the delegate goes away.
-  MediaStreamAudioSink* delegate_;
-
-  DISALLOW_COPY_AND_ASSIGN(MediaStreamAudioSinkOwner);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_SINK_OWNER_H_