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

media/renderers/audio_renderer_impl.cc

Index: media/renderers/audio_renderer_impl.cc
diff --git a/media/renderers/audio_renderer_impl.cc b/media/renderers/audio_renderer_impl.cc
index 2d9879b64b814f8fa6c91dbdec925ded880d69a9..180c262079a958a41921daecc3f39b8b25d76091 100644
--- a/media/renderers/audio_renderer_impl.cc
+++ b/media/renderers/audio_renderer_impl.cc
@@ -334,6 +334,7 @@ void AudioRendererImpl::Initialize(
   buffering_state_cb_ = buffering_state_cb;
   ended_cb_ = ended_cb;
   error_cb_ = error_cb;
+  statistics_cb_ = statistics_cb;
 
   const AudioParameters& hw_params = hardware_config_.GetOutputConfig();
   expecting_config_changes_ = stream->SupportsConfigChanges();
@@ -514,6 +515,10 @@ bool AudioRendererImpl::HandleSplicerBuffer_Locked(
   if (first_packet_timestamp_ == kNoTimestamp())
     first_packet_timestamp_ = buffer->timestamp();
 
+  PipelineStatistics stats;
+  stats.audio_memory_usage = algorithm_->GetMemoryUsage();
+  statistics_cb_.Run(stats);
+
   switch (state_) {
     case kUninitialized:
     case kInitializing: