Stop media stream source when audio capture error occurs.

content/renderer/media/local_media_stream_audio_source.cc

Index: content/renderer/media/local_media_stream_audio_source.cc
diff --git a/content/renderer/media/local_media_stream_audio_source.cc b/content/renderer/media/local_media_stream_audio_source.cc
index f2075b97723c950424a5c49de547843d276ac3c5..78ea116288c5f92b2de25cc30fb561361d196e0f 100644
--- a/content/renderer/media/local_media_stream_audio_source.cc
+++ b/content/renderer/media/local_media_stream_audio_source.cc
@@ -4,6 +4,8 @@
 
 #include "content/renderer/media/local_media_stream_audio_source.h"
 
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "content/common/media/media_stream_options.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/render_frame_impl.h"
@@ -14,7 +16,8 @@ LocalMediaStreamAudioSource::LocalMediaStreamAudioSource(
     int consumer_render_frame_id,
     const StreamDeviceInfo& device_info)
     : MediaStreamAudioSource(true /* is_local_source */),
-      consumer_render_frame_id_(consumer_render_frame_id) {
+      consumer_render_frame_id_(consumer_render_frame_id),
+      task_runner_(base::ThreadTaskRunnerHandle::Get()) {
   DVLOG(1) << "LocalMediaStreamAudioSource::LocalMediaStreamAudioSource()";
   MediaStreamSource::SetDeviceInfo(device_info);
 
@@ -99,10 +102,11 @@ void LocalMediaStreamAudioSource::Capture(const media::AudioBus* audio_bus,
 }
 
 void LocalMediaStreamAudioSource::OnCaptureError(const std::string& why) {
-  // As of this writing, this method doesn't get called for anything useful,
-  // and all other implementors just log the message, but don't disconnect sinks
-  // or take any other action. So, just log the error.
-  LOG(ERROR) << why;
+  VLOG(1) << why;
+
+  // Stop source when error occurs.
+  task_runner_->PostTask(
+      FROM_HERE, base::Bind(&MediaStreamSource::StopSource, AsWeakPtr()));

[miu, 2016/10/14 05:38:26]

Why do we need the task runner? Isn't OnCaptureError() always called on the main
thread?

Also, I'm not sure it's a good idea to close the source here. Instead, the
onEnded event should be sent via the tracks. 

[xjz, 2016/10/14 17:32:53]

When tab is closed, this is called on io thread, not main thread. 
When calling MediaStreamSource::StopSource, it will call setReadyState() and the
track will send onEnded event. I did this in the similar way as that is done for
video capture source. Not sure if this is the best way either.

 }
 
 }  // namespace content