Switching to I420VideoFrame

Review URL: https://webrtc-codereview.appspot.com/922004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@2983 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video_engine/vie_encoder.h b/video_engine/vie_encoder.h
index dc74f33..339390f 100644
--- a/video_engine/vie_encoder.h
+++ b/video_engine/vie_encoder.h
@@ -84,7 +84,7 @@
 
   // Implementing ViEFrameCallback.
   virtual void DeliverFrame(int id,
-                            VideoFrame* video_frame,
+                            I420VideoFrame* video_frame,
                             int num_csrcs = 0,
                             const WebRtc_UWord32 CSRC[kRtpCsrcSize] = NULL);
   virtual void DelayChanged(int id, int frame_delay);