Fixed the crash when adding a chromium sink to remote audio track or

content/public/renderer/media_stream_audio_sink.cc

Index: content/public/renderer/media_stream_audio_sink.cc
diff --git a/content/public/renderer/media_stream_audio_sink.cc b/content/public/renderer/media_stream_audio_sink.cc
index 9d105d9c36f4b893790a40554e280aab438cf2fd..142ceeae38d3699bfe05e47e29d7cb48340677ad 100644
--- a/content/public/renderer/media_stream_audio_sink.cc
+++ b/content/public/renderer/media_stream_audio_sink.cc
@@ -18,7 +18,11 @@ void MediaStreamAudioSink::AddToAudioTrack(
   DCHECK(track.source().type() == blink::WebMediaStreamSource::TypeAudio);
   MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track);
   // TODO(xians): Support remote audio track.
-  DCHECK(native_track->is_local_track());
+  if (!native_track->is_local_track()) {
+    LOG(ERROR) << "Only local audio track is supported now";

[Ronghua Wu (Left Chromium), 2014/07/23 15:53:42]

add info about what is "supported".

E.g. Can't add a remote track to a local stream.

[no longer working on chromium, 2014/07/24 13:23:31]

Done.

+    return;
+  }
+
   WebRtcLocalAudioTrack* audio_track =
       static_cast<WebRtcLocalAudioTrack*>(native_track);
   audio_track->AddSink(sink);
@@ -29,7 +33,11 @@ void MediaStreamAudioSink::RemoveFromAudioTrack(
     const blink::WebMediaStreamTrack& track) {
   MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track);
   // TODO(xians): Support remote audio track.
-  DCHECK(native_track->is_local_track());
+  if (!native_track->is_local_track()) {
+    LOG(ERROR) << "Only local audio track is supported now";

[Ronghua Wu (Left Chromium), 2014/07/23 15:53:42]

dito

[no longer working on chromium, 2014/07/24 13:23:31]

Done.

+    return;
+  }
+
   WebRtcLocalAudioTrack* audio_track =
       static_cast<WebRtcLocalAudioTrack*>(native_track);
   audio_track->RemoveSink(sink);