Implement ConstraintNotSatisfiedError for getusermedia

content/renderer/media/media_stream_video_source.h

Index: content/renderer/media/media_stream_video_source.h
diff --git a/content/renderer/media/media_stream_video_source.h b/content/renderer/media/media_stream_video_source.h
index c2f6f179366a25d8b0b8c4875dd80b4ff8088778..1d7c016a71603bff92bc49db2e9cbe027bb69869 100644
--- a/content/renderer/media/media_stream_video_source.h
+++ b/content/renderer/media/media_stream_video_source.h
@@ -111,7 +111,7 @@ class CONTENT_EXPORT MediaStreamVideoSource
   virtual void StartSourceImpl(
       const media::VideoCaptureParams& params,
       const VideoCaptureDeliverFrameCB& frame_callback) = 0;
-  void OnStartDone(bool success);
+  void OnStartDone(MediaStreamRequestResult result);
 
   // An implementation must immediately stop capture video frames and must not
   // call OnSupportedFormats after this method has been called. After this
@@ -144,11 +144,14 @@ class CONTENT_EXPORT MediaStreamVideoSource
   // in the context of the callback. If gUM fail, the implementation will
   // simply drop the references to the blink source and track which will lead
   // to that this object is deleted.
-  void FinalizeAddTrack();
+  void FinalizeAddTrack(MediaStreamRequestResult result);
 
   State state_;
   bool muted_state_;
 
+  // unsatisfied_constraint_ is used to record the name of constraint
+  // that causes ConstraintNotSatisfiedError
+  blink::WebString unsatisfied_constraint_;

[miu, 2014/07/30 19:37:23]

You don't want this here, as it obfuscates the lifetime of this string and the
code path that uses it.

Instead, you should pass it along the call stack.  See comment in .cc file for
more details.

[jiajia.qin, 2014/07/31 13:43:01]

Done.

   media::VideoCaptureFormat current_format_;
 
   struct RequestedConstraints {