Fix gradual deterioration of cadence based rendering.

media/filters/video_renderer_algorithm.h

Index: media/filters/video_renderer_algorithm.h
diff --git a/media/filters/video_renderer_algorithm.h b/media/filters/video_renderer_algorithm.h
index ee4d4c4e6f2e616d22e2ae92502992ba0e9fa304..4a3da250815eea1979e118259b823db737c9a934 100644
--- a/media/filters/video_renderer_algorithm.h
+++ b/media/filters/video_renderer_algorithm.h
@@ -300,6 +300,10 @@ class MEDIA_EXPORT VideoRendererAlgorithm {
   // ReadyFrameQueue.  Cleared when a new cadence is detected.
   uint64_t cadence_frame_counter_;
 
+  // Tracks whether the last call to Render() choose to ignore the frame chosen
+  // by cadence in favor of one by drift or coverage.
+  bool last_render_ignored_cadence_frame_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoRendererAlgorithm);
 };