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

media/filters/video_renderer_algorithm.cc

Index: media/filters/video_renderer_algorithm.cc
diff --git a/media/filters/video_renderer_algorithm.cc b/media/filters/video_renderer_algorithm.cc
index bbb48648767b8f5b6da7fb4cda321b0b7c42647e..f9205352f26e0ebd3482cfecb02712dbb912e069 100644
--- a/media/filters/video_renderer_algorithm.cc
+++ b/media/filters/video_renderer_algorithm.cc
@@ -350,6 +350,15 @@ size_t VideoRendererAlgorithm::EffectiveFramesQueued() const {
   return renderable_frame_count;
 }
 
+int64_t VideoRendererAlgorithm::GetMemoryUsage() const {
+  int64_t allocation_size = 0;
+  for (const auto& v : frame_queue_) {
+    allocation_size +=
+        VideoFrame::AllocationSize(v.frame->format(), v.frame->coded_size());
+  }
+  return allocation_size;
+}
+
 void VideoRendererAlgorithm::EnqueueFrame(
     const scoped_refptr<VideoFrame>& frame) {
   DCHECK(frame);