Revert of Delete webrtc::VideoFrame::CopyFrame.

webrtc/video_frame.h

Index: webrtc/video_frame.h
diff --git a/webrtc/video_frame.h b/webrtc/video_frame.h
index b01555e09288187723a5cf7570aea23be565dfee..21654d95e4fe512df08f48c1ccf4a9992cb4b2cd 100644
--- a/webrtc/video_frame.h
+++ b/webrtc/video_frame.h
@@ -69,6 +69,13 @@
                   int width,
                   int height,
                   VideoRotation rotation);
+
+  // Deep copy frame: If required size is bigger than allocated one, new
+  // buffers of adequate size will be allocated.
+  // TODO(nisse): Should be deleted in the cricket::VideoFrame and
+  // webrtc::VideoFrame merge. Instead, use I420Buffer::Copy to make a copy of
+  // the pixel data, and use the constructor to wrap it into a VideoFrame.
+  void CopyFrame(const VideoFrame& videoFrame);
 
   // Creates a shallow copy of |videoFrame|, i.e, the this object will retain a
   // reference to the video buffer also retained by |videoFrame|.