Revert of Remove AudioTrackRenderer

talk/app/webrtc/audiotrackrenderer.h

+/*
+ * libjingle
+ * Copyright 2013 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef TALK_APP_WEBRTC_AUDIOTRACKRENDERER_H_
+#define TALK_APP_WEBRTC_AUDIOTRACKRENDERER_H_
+
+#include "talk/media/base/audiorenderer.h"
+#include "webrtc/base/thread.h"
+
+namespace webrtc {
+
+// Class used for AudioTrack to get the ID of WebRtc voice channel that
+// the AudioTrack is connecting to.
+// Each AudioTrack owns a AudioTrackRenderer instance.
+// AddChannel() will be called when an AudioTrack is added to a MediaStream.
+// RemoveChannel will be called when the AudioTrack or WebRtc VoE channel is
+// going away.
+// This implementation only supports one channel, and it is only used by
+// Chrome for remote audio tracks."
+class AudioTrackRenderer : public cricket::AudioRenderer {
+ public:
+  AudioTrackRenderer();
+  ~AudioTrackRenderer();
+
+  // Implements cricket::AudioRenderer.
+  void AddChannel(int channel_id) override;
+  void RemoveChannel(int channel_id) override;
+
+ private:
+  int channel_id_;
+};
+
+}  // namespace webrtc
+
+#endif  // TALK_APP_WEBRTC_AUDIOTRACKRENDERER_H_