Deletes the class VideoRendererCallback.

webrtc/modules/video_render/mac/video_render_nsopengl.mm

Index: webrtc/modules/video_render/mac/video_render_nsopengl.mm
diff --git a/webrtc/modules/video_render/mac/video_render_nsopengl.mm b/webrtc/modules/video_render/mac/video_render_nsopengl.mm
index b7683a96af4895b078de5d9b4323e15f4da3d37b..aaf242e5ab150bfb32c94722a2327d2b444f1174 100644
--- a/webrtc/modules/video_render/mac/video_render_nsopengl.mm
+++ b/webrtc/modules/video_render/mac/video_render_nsopengl.mm
@@ -89,21 +89,18 @@ int32_t VideoChannelNSOpenGL::GetChannelProperties(float& left, float& top,
     return 0;
 }
 
-int32_t VideoChannelNSOpenGL::RenderFrame(const uint32_t /*streamId*/,
-                                          const VideoFrame& videoFrame) {
+void VideoChannelNSOpenGL::OnFrame(const VideoFrame& videoFrame) {
   _owner->LockAGLCntx();
 
   if(_width != videoFrame.width() ||
      _height != videoFrame.height()) {
       if(FrameSizeChange(videoFrame.width(), videoFrame.height(), 1) == -1) {
         _owner->UnlockAGLCntx();
-        return -1;
+        return;
       }
   }
-  int ret = DeliverFrame(videoFrame);
-
+  DeliverFrame(videoFrame);
   _owner->UnlockAGLCntx();
-  return ret;
 }
 
 int VideoChannelNSOpenGL::UpdateSize(int width, int height)