Add methods for telling V8 how much memory audio/video is using.

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 71d251f416a667e9515afb779d776bdbbffba12d..88039b56da0ffed5d60024831f55d05e88482ec6 100644
--- a/media/filters/video_renderer_algorithm.h
+++ b/media/filters/video_renderer_algorithm.h
@@ -117,6 +117,9 @@ class MEDIA_EXPORT VideoRendererAlgorithm {
   // be counted as effective.
   size_t EffectiveFramesQueued() const;
 
+  // Returns an estimate of the amount of memory used for decoded frames.
+  int64_t GetMemoryUsage() const;
+
   // Tells the algorithm that Render() callbacks have been suspended for a known
   // reason and such stoppage shouldn't be counted against future frames.
   void set_time_stopped() { was_time_moving_ = false; }