Revert of Delete webrtc::VideoFrame methods buffer and stride.

webrtc/media/base/videoframe.h

Index: webrtc/media/base/videoframe.h
diff --git a/webrtc/media/base/videoframe.h b/webrtc/media/base/videoframe.h
index 596706f268a117244f57ef60b8ec7aab46de77af..9e0fbfd6d42ceff6f036935392b06dad54bee4d3 100644
--- a/webrtc/media/base/videoframe.h
+++ b/webrtc/media/base/videoframe.h
@@ -54,8 +54,6 @@
 
   // Returns the underlying video frame buffer. This function is ok to call
   // multiple times, but the returned object will refer to the same memory.
-  // TODO(nisse): Change to return a const ref to a scoped_refptr, for
-  // consistency with webrtc::VideoFrame.
   virtual rtc::scoped_refptr<webrtc::VideoFrameBuffer> video_frame_buffer()
       const = 0;