Use texture-backed VideoFrame pipeline for Aura desktop capturing.

content/renderer/media/webrtc/media_stream_remote_video_source.cc

Index: content/renderer/media/webrtc/media_stream_remote_video_source.cc
diff --git a/content/renderer/media/webrtc/media_stream_remote_video_source.cc b/content/renderer/media/webrtc/media_stream_remote_video_source.cc
index 39865aae545aedc0aa05f2e324957c2c56945394..0f865cf2706a4283f9c0cbe3790499fb6edd7590 100644
--- a/content/renderer/media/webrtc/media_stream_remote_video_source.cc
+++ b/content/renderer/media/webrtc/media_stream_remote_video_source.cc
@@ -64,9 +64,7 @@ void MediaStreamRemoteVideoSource::RenderFrame(
 
   scoped_refptr<media::VideoFrame> video_frame;
   if (frame->GetNativeHandle() != NULL) {
-    NativeHandleImpl* handle =
-        static_cast<NativeHandleImpl*>(frame->GetNativeHandle());
-    video_frame = static_cast<media::VideoFrame*>(handle->GetHandle());
+    video_frame = static_cast<media::VideoFrame*>(frame->GetNativeHandle());

[Ami GONE FROM CHROMIUM, 2014/04/30 03:03:43]

urr, wat?

What happened in this thunk?

[hshi1, 2014/04/30 18:05:19]

I actually don't think this change is correct, we should revert this file.

The cricket::VideoFrame::GetNativeHandle() returns a valid (void*) handle if the
VideoFrame object is an instance of class cricket::WebRtcTextureVideoFrame.
Aside from a trivial copy constructor, the only path I found to construct such
an instance is via call WebRtcVideoEngine::DeliverFrame() ->
WebRtcVideoEngine::DeliverTextureFrame().

Example of call to DeliverFrame() with valid handle: vie_renderer.cc:
ViEExternalRendererImpl::RenderFrame() where the handle comes from
webrtc::TextureVideoFrame::native_handle().

Example of constructor of webrtc::TextureVideoFrame is seen in
RTCVideoDecoder::PictureReady() where we supply the handle as new
webrtc::RefCountImpl<NativeHandleImpl>(media::VideoFrame).

Thus, the frame->GetNativeHandle() should be first static_cast'ed to
NativeHandleImpl* and then we obtain media::VideoFrame* pointer with
NativeHandleImpl::GetHandle(), as originally written.

     video_frame->set_timestamp(timestamp);
   } else {
     gfx::Size size(frame->GetWidth(), frame->GetHeight());