Move getUserMedia finish to "when audio track configured".

content/renderer/media/media_stream_audio_track.cc

Index: content/renderer/media/media_stream_audio_track.cc
diff --git a/content/renderer/media/media_stream_audio_track.cc b/content/renderer/media/media_stream_audio_track.cc
index cb64f8af18db392cdee6789560a9c5e0659857c3..4c84585d689c5160de661cf09042c327e04b2d80 100644
--- a/content/renderer/media/media_stream_audio_track.cc
+++ b/content/renderer/media/media_stream_audio_track.cc
@@ -118,6 +118,18 @@ void MediaStreamAudioTrack::Stop() {
 }
 
 void MediaStreamAudioTrack::OnSetFormat(const media::AudioParameters& params) {
+  format_is_set_ = true;
+  base::OnceCallback<void()> temp_callback;
+  // Call the callback if present, but don't hold a lock while doing so.
+  {
+    base::AutoLock guard(format_set_callback_guard_);
+    if (!format_set_callback_.is_null()) {
+      temp_callback = std::move(format_set_callback_);
+    }
+  }
+  if (!temp_callback.is_null()) {
+    std::move(temp_callback).Run();
+  }
   deliverer_.OnSetFormat(params);
 }
 
@@ -143,8 +155,7 @@ void MediaStreamAudioTrack::OnData(const media::AudioBus& audio_bus,
 
 void MediaStreamAudioTrack::getSettings(
     blink::WebMediaStreamTrack::Settings& settings) {
-  // TODO(hta): Extract the real value.
-  settings.deviceId = blink::WebString("audio device ID");
+  DCHECK(format_is_set_);

[Guido Urdaneta, 2017/04/06 13:18:57]

Does format_is_set_ need to be protected by the lock?
If so, use  #if DCHECK_IS_ON() around the DCHECK.

[hta - Chromium, 2017/04/06 13:57:51]

I put it on protection; not sure it's required for bools, but better be safe
than sorry. I used an accessor to avoid the extra visual noise of #if
DCHECK_IS_ON.

[Guido Urdaneta, 2017/04/06 14:01:05]

You solved it in a nicer way :)

 }
 
 }  // namespace content