Make painting a single frame a permanent API on VideoRendererSink.

media/base/null_video_sink.h

Index: media/base/null_video_sink.h
diff --git a/media/base/null_video_sink.h b/media/base/null_video_sink.h
index ca298b61fbaf1db0d11a6bea19a90d8985015340..3c458744b1390759476415d193795f92d29a0c56 100644
--- a/media/base/null_video_sink.h
+++ b/media/base/null_video_sink.h
@@ -35,8 +35,7 @@ class MEDIA_EXPORT NullVideoSink : public VideoRendererSink {
   // VideoRendererSink implementation.
   void Start(RenderCallback* callback) override;
   void Stop() override;
-  void PaintFrameUsingOldRenderingPath(
-      const scoped_refptr<VideoFrame>& frame) override;
+  void PaintSingleFrame(const scoped_refptr<VideoFrame>& frame) override;
 
   void set_tick_clock_for_testing(base::TickClock* tick_clock) {
     tick_clock_ = tick_clock;