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

content/renderer/media/media_stream_audio_sink_owner.cc

+// 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.
+
+#include "content/renderer/media/media_stream_audio_sink_owner.h"
+
+namespace content {
+
+MediaStreamAudioSinkOwner::MediaStreamAudioSinkOwner(
+    MediaStreamAudioSink* sink)
+    : media_stream_delegate_(sink),
+      peer_connection_delegate_(NULL) {
+}
+
+MediaStreamAudioSinkOwner::MediaStreamAudioSinkOwner(
+    PeerConnectionAudioSink* sink)
+    : media_stream_delegate_(NULL),
+      peer_connection_delegate_(sink) {
+}
+
+int MediaStreamAudioSinkOwner::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) {
+  base::AutoLock lock(lock_);
+  if (media_stream_delegate_) {
+    DCHECK(!peer_connection_delegate_);
+    media_stream_delegate_->OnData(audio_data,
+                                   sample_rate,
+                                   number_of_channels,
+                                   number_of_frames);
+    return 0;
+  }
+
+  if (peer_connection_delegate_) {
+    return peer_connection_delegate_->OnData(audio_data,
+                                             sample_rate,
+                                             number_of_channels,
+                                             number_of_frames,
+                                             channels,
+                                             audio_delay_milliseconds,
+                                             current_volume,
+                                             need_audio_processing,
+                                             key_pressed);
+  }
+
+  return 0;
+}
+
+void MediaStreamAudioSinkOwner::OnSetFormat(
+    const media::AudioParameters& params) {
+  base::AutoLock lock(lock_);
+  if (media_stream_delegate_) {
+    DCHECK(!peer_connection_delegate_);
+    media_stream_delegate_->OnSetFormat(params);
+    return;
+  }
+
+  if (peer_connection_delegate_)
+    peer_connection_delegate_->OnSetFormat(params);
+}
+
+bool MediaStreamAudioSinkOwner::IsEqual(

[Jói, 2013/11/27 17:35:02]

This will return true if |other| is NULL and media_stream_delegate_ is NULL,
while peer_connection_delegate_ might be the one being used and might be
non-NULL.

Same thing for the other IsEqual implementation.

You need to special case the |other == NULL| case and only return true if both
media_stream_delegate_ and peer_connection_delegate_ are NULL.

[no longer working on chromium, 2013/11/28 17:27:18]

Added a DCHECK(other);

[no longer working on chromium, 2013/11/28 19:22:22]

I just realized that I forgot to commit the local change on adding DCHECK here,
but I will do it tomorrow after I get back to the office.

+    const MediaStreamAudioSink* other) const {
+  base::AutoLock lock(lock_);
+  return (other == media_stream_delegate_);
+}
+
+bool MediaStreamAudioSinkOwner::IsEqual(
+    const PeerConnectionAudioSink* other) const {
+  base::AutoLock lock(lock_);
+  return (other == peer_connection_delegate_);
+}
+
+void MediaStreamAudioSinkOwner::Reset() {
+  base::AutoLock lock(lock_);
+  media_stream_delegate_ = NULL;
+  peer_connection_delegate_ = NULL;
+}
+
+}  // namespace content