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

media/blink/webmediaplayer_impl.h

Index: media/blink/webmediaplayer_impl.h
diff --git a/media/blink/webmediaplayer_impl.h b/media/blink/webmediaplayer_impl.h
index 75e538afa3260f73e47ebfe8ce72297b8258545b..381ebcdac5ab7562c56299ca5ee3beceb929ec69 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -234,6 +234,10 @@ class MEDIA_EXPORT WebMediaPlayerImpl
   // |ended_| state by clamping current time to duration upon |ended_|.
   void UpdatePausedTime();
 
+  // Called at low frequency to tell external observers how much memory we're
+  // using for video playback.  Called by |memory_usage_reporting_timer_|.
+  void ReportMemoryUsage();
+
   blink::WebLocalFrame* frame_;
 
   // TODO(hclam): get rid of these members and read from the pipeline directly.
@@ -301,6 +305,10 @@ class MEDIA_EXPORT WebMediaPlayerImpl
   WebMediaPlayerParams::DeferLoadCB defer_load_cb_;
   WebMediaPlayerParams::Context3DCB context_3d_cb_;
 
+  base::RepeatingTimer memory_usage_reporting_timer_;
+  WebMediaPlayerParams::AdjustAllocatedMemoryCB adjust_allocated_memory_cb_;
+  int64_t last_reported_memory_usage_;
+
   // Routes audio playback to either AudioRendererSink or WebAudio.
   scoped_refptr<WebAudioSourceProviderImpl> audio_source_provider_;