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

content/renderer/media/media_stream_audio_track_sink.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_TRACK_SINK_H_
-#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_TRACK_SINK_H_
-
-#include <vector>
-
-#include "base/logging.h"
-#include "base/memory/ref_counted.h"
-#include "base/time/time.h"
-#include "media/base/audio_parameters.h"
-#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
-
-namespace media {
-class AudioBus;
-}
-
-namespace content {
-
-class MediaStreamAudioSink;
-
-// Interface for reference counted holder of audio stream audio track sink.
-class MediaStreamAudioTrackSink
-    : public base::RefCountedThreadSafe<MediaStreamAudioTrackSink> {
- public:
-  // Note: OnData() and OnSetFormat() have the same meaning and semantics as in
-  // content::MediaStreamAudioSink.  See comments there for usage info.
-  virtual void OnData(const media::AudioBus& audio_bus,
-                      base::TimeTicks estimated_capture_time) = 0;
-  virtual void OnSetFormat(const media::AudioParameters& params) = 0;
-
-  virtual void OnReadyStateChanged(
-      blink::WebMediaStreamSource::ReadyState state) = 0;
-
-  virtual void Reset() = 0;
-
-  virtual bool IsEqual(const MediaStreamAudioSink* other) const = 0;
-
-  // Wrapper which allows to use std::find_if() when adding and removing
-  // sinks to/from the list.
-  struct WrapsMediaStreamSink {
-    WrapsMediaStreamSink(MediaStreamAudioSink* sink) : sink_(sink) {}
-    bool operator()(
-        const scoped_refptr<MediaStreamAudioTrackSink>& owner) const {
-      return owner->IsEqual(sink_);
-    }
-    MediaStreamAudioSink* sink_;
-  };
-
- protected:
-  virtual ~MediaStreamAudioTrackSink() {}
-
- private:
-  friend class base::RefCountedThreadSafe<MediaStreamAudioTrackSink>;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_TRACK_SINK_H_