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

media/renderers/video_renderer_impl.cc

Index: media/renderers/video_renderer_impl.cc
diff --git a/media/renderers/video_renderer_impl.cc b/media/renderers/video_renderer_impl.cc
index 3596ece66fdc57363eed4df8c6cf21e6dfa1ce52..4f7f9caff58007fc13d65b45eb9997ccc5df87cb 100644
--- a/media/renderers/video_renderer_impl.cc
+++ b/media/renderers/video_renderer_impl.cc
@@ -550,6 +550,7 @@ void VideoRendererImpl::UpdateStats_Locked() {
     PipelineStatistics statistics;
     statistics.video_frames_decoded = frames_decoded_;
     statistics.video_frames_dropped = frames_dropped_;
+    statistics.video_memory_usage = algorithm_->GetMemoryUsage();
     task_runner_->PostTask(FROM_HERE, base::Bind(statistics_cb_, statistics));
 
     frames_decoded_ = 0;