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..deb8dfe2111ce7f7f670d0907e9e813d45600370 100644
--- a/media/renderers/audio_renderer_impl.cc
+++ b/media/renderers/audio_renderer_impl.cc
@@ -57,6 +57,7 @@ AudioRendererImpl::AudioRendererImpl(
       hardware_config_(hardware_config),
       media_log_(media_log),
       tick_clock_(new base::DefaultTickClock()),
+      last_audio_memory_usage_(0),
       playback_rate_(0.0),
       state_(kUninitialized),
       buffering_state_(BUFFERING_HAVE_NOTHING),
@@ -334,6 +335,7 @@ 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 +516,12 @@ bool AudioRendererImpl::HandleSplicerBuffer_Locked(
   if (first_packet_timestamp_ == kNoTimestamp())
     first_packet_timestamp_ = buffer->timestamp();
 
+  const size_t memory_usage = algorithm_->GetMemoryUsage();
+  PipelineStatistics stats;
+  stats.audio_memory_usage = memory_usage - last_audio_memory_usage_;
+  last_audio_memory_usage_ = memory_usage;
+  task_runner_->PostTask(FROM_HERE, base::Bind(statistics_cb_, stats));
+
   switch (state_) {
     case kUninitialized:
     case kInitializing: