Make painting a single frame a permanent API on VideoRendererSink.

media/base/null_video_sink.cc

Index: media/base/null_video_sink.cc
diff --git a/media/base/null_video_sink.cc b/media/base/null_video_sink.cc
index f8471056c99c85f6b9f185d5c046adbe05ade819..e96fdda240dcbc4beaa19a2286b6d6d63ce9413b 100644
--- a/media/base/null_video_sink.cc
+++ b/media/base/null_video_sink.cc
@@ -88,8 +88,7 @@ void NullVideoSink::CallRender() {
                                 delay);
 }
 
-void NullVideoSink::PaintFrameUsingOldRenderingPath(
-    const scoped_refptr<VideoFrame>& frame) {
+void NullVideoSink::PaintSingleFrame(const scoped_refptr<VideoFrame>& frame) {
   new_frame_cb_.Run(frame);
 }