MediaStreamVideoSource exports current video format

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 cd40375079756c351c30a01de463b1ff9aa25864..8ebc7b70e914b84ac854a19d70ed2947d1619a5d 100644
--- a/content/renderer/media/media_stream_video_source.h
+++ b/content/renderer/media/media_stream_video_source.h
@@ -87,6 +87,8 @@ class CONTENT_EXPORT MediaStreamVideoSource
   // Returns the task runner where video frames will be delivered on.
   base::SingleThreadTaskRunner* io_task_runner() const;
 
+  media::VideoCaptureFormat current_format() const { return current_format_; }

[miu, 2016/02/05 22:20:47]

The format is invalid until the source is started.  Also, there are
thread-safety concerns here.  IMO, I think the method should look something like
the following:

  // Returns the current video format of this source, or null if it has not yet
been determined.
  const media::VideoCaptureFormat* current_format() const {
    DCHECK(CalledOnValidThread());
    if (state_ == STARTING || state_ == STARTED)
      return &current_format_;
    return nullptr;
  }

[miu, 2016/02/05 22:20:47]

Where is the code that calls this?  Note that there's a danger this method could
be removed if a project member does not see it being called from anywhere.  You
should probably just punt on this code review, and include this new method in
the change where you have code that calls it.

[Mikhail, 2016/02/08 08:13:06]

I will reference this CL when upload the client code. thanks

+
  protected:
   void DoStopSource() override;