Add generic interfaces for the sinks of the media stream audio track

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 "media/audio/audio_parameters.h"
+
+namespace content {
+
+class MediaStreamAudioSink;
+class PeerConnectionAudioSink;
+
+// Interface for reference counted holder of audio stream audio track sink.
+class MediaStreamAudioTrackSink
+    : public base::RefCountedThreadSafe<MediaStreamAudioTrackSink> {
+ public:
+   virtual int OnData(const int16* audio_data,
+                      int sample_rate,
+                      int number_of_channels,
+                      int number_of_frames,
+                      const std::vector<int>& channels,
+                      int audio_delay_milliseconds,
+                      int current_volume,
+                      bool need_audio_processing,
+                      bool key_pressed) = 0;
+
+  virtual void OnSetFormat(const media::AudioParameters& params) = 0;
+
+  virtual void Reset() = 0;
+
+  virtual bool IsEqual(const MediaStreamAudioSink* other) const = 0;
+  virtual bool IsEqual(const PeerConnectionAudioSink* 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) {
+      return owner->IsEqual(sink_);
+    }
+    MediaStreamAudioSink* sink_;
+  };
+  struct WrapsPeerConnectionSink {
+    WrapsPeerConnectionSink(PeerConnectionAudioSink* sink) : sink_(sink) {}
+    bool operator()(const scoped_refptr<MediaStreamAudioTrackSink>& owner) {
+      return owner->IsEqual(sink_);
+    }
+    PeerConnectionAudioSink* sink_;
+  };
+
+ protected:
+  virtual ~MediaStreamAudioTrackSink() {}
+
+ private:
+  friend class base::RefCountedThreadSafe<MediaStreamAudioTrackSink>;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_TRACK_SINK_H_