Delete method cricket::VideoFrame::Copy.

Should be unused in Chrome since cl
https://codereview.chromium.org/2068703002/

TBR=tkchin@webrtc.org,magjed@webrtc.org
BUG=webrtc:5682

Review-Url: https://codereview.webrtc.org/2080253002
Cr-Original-Commit-Position: refs/heads/master@{#13236}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 9c00f646f0b3cd33506a1944c7bc6724af041237

app/webrtc/objc/RTCI420Frame.mm

diff --git a/app/webrtc/objc/RTCI420Frame.mm b/app/webrtc/objc/RTCI420Frame.mm
index 6c6c564..1646510 100644
--- a/app/webrtc/objc/RTCI420Frame.mm
+++ b/app/webrtc/objc/RTCI420Frame.mm
@@ -29,7 +29,7 @@
 
 #include <memory>
 
-#include "webrtc/media/base/videoframe.h"
+#include "webrtc/media/engine/webrtcvideoframe.h"
 
 @implementation RTCI420Frame {
   std::unique_ptr<cricket::VideoFrame> _videoFrame;
@@ -98,7 +98,10 @@
   if (self = [super init]) {
     // Keep a shallow copy of the video frame. The underlying frame buffer is
     // not copied.
-    _videoFrame.reset(videoFrame->Copy());
+    _videoFrame.reset(new cricket::WebRtcVideoFrame(
+        videoFrame->video_frame_buffer(),
+        videoFrame->rotation(),
+        videoFrame->timestamp_us()));
   }
   return self;
 }