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

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index bee9dae7d4bf96ad51364d16362d77d3c4f0dd28..968b8337e745c33ce9bdd8a46cca04e8fbb99ec6 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -147,6 +147,8 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
       delegate_(delegate),
       defer_load_cb_(params.defer_load_cb()),
       context_3d_cb_(params.context_3d_cb()),
+      adjust_allocated_memory_cb_(params.adjust_allocated_memory_cb()),
+      last_reported_memory_usage_(0),
       supports_save_(true),
       chunk_demuxer_(NULL),
       // Threaded compositing isn't enabled universally yet.
@@ -209,6 +211,9 @@ WebMediaPlayerImpl::~WebMediaPlayerImpl() {
       base::Bind(&base::WaitableEvent::Signal, base::Unretained(&waiter)));
   waiter.Wait();
 
+  if (last_reported_memory_usage_)
+    adjust_allocated_memory_cb_.Run(-last_reported_memory_usage_);
+
   compositor_task_runner_->DeleteSoon(FROM_HERE, compositor_);
 
   media_log_->AddEvent(
@@ -244,6 +249,9 @@ void WebMediaPlayerImpl::DoLoad(LoadType load_type,
   SetNetworkState(WebMediaPlayer::NetworkStateLoading);
   SetReadyState(WebMediaPlayer::ReadyStateHaveNothing);
   media_log_->AddEvent(media_log_->CreateLoadEvent(url.spec()));
+  memory_usage_reporting_timer_.Start(
+      FROM_HERE, base::TimeDelta::FromMilliseconds(500), this,

[xhwang, 2015/10/25 17:01:56]

Is 500ms recommended by v8? I know nothing about this area but just want to
double check....

[DaleCurtis, 2015/10/27 23:14:20]

Chosen arbitrarily. ulan@, jochen@ Does this value seem reasonable?

[ulan, 2015/10/28 13:22:09]

Yes, but the value is not v8 specific so I am not sure if it is better than any
other value.

+      &WebMediaPlayerImpl::ReportMemoryUsage);
 
   // Media source pipelines can start immediately.
   if (load_type == LoadTypeMediaSource) {
@@ -1083,4 +1091,23 @@ void WebMediaPlayerImpl::UpdatePausedTime() {
       ended_ ? pipeline_.GetMediaDuration() : pipeline_.GetMediaTime();
 }
 
+void WebMediaPlayerImpl::ReportMemoryUsage() {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+
+  const PipelineStatistics stats = pipeline_.GetStatistics();
+  const int64_t current_memory_usage =
+      stats.audio_memory_usage + stats.video_memory_usage +
+      (data_source_ ? data_source_->GetMemoryUsage() : 0) +
+      (demuxer_ ? demuxer_->GetMemoryUsage() : 0);
+
+  DVLOG(2) << "Memory Usage -- Audio: " << stats.audio_memory_usage
+           << ", Video: " << stats.video_memory_usage << ", DataSource: "
+           << (data_source_ ? data_source_->GetMemoryUsage() : 0)
+           << ", Demuxer: " << (demuxer_ ? demuxer_->GetMemoryUsage() : 0);
+
+  const int64_t delta = current_memory_usage - last_reported_memory_usage_;
+  last_reported_memory_usage_ = current_memory_usage;
+  adjust_allocated_memory_cb_.Run(delta);

[xhwang, 2015/10/25 17:01:56]

If |delta| is zero or very small, should we still report? (Not sure what's the
cost of this call :)

[DaleCurtis, 2015/10/27 23:14:20]

ulan@, jochen@: WDYT?

[ulan, 2015/10/28 13:22:09]

It is fine to report.

Zero delta would be a no-op, the cost is function call + several memory
accesses.

+}
+
 }  // namespace media