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

media/base/pipeline.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/pipeline.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 28 matching lines @@
       volume_(1.0f),
       playback_rate_(0.0),
       status_(PIPELINE_OK),
       state_(kCreated),
       renderer_ended_(false),
       text_renderer_ended_(false),
       demuxer_(NULL),
       pending_cdm_context_(nullptr),
       weak_factory_(this) {
   media_log_->AddEvent(media_log_->CreatePipelineStateChangedEvent(kCreated));
+
+  // By default these values are initialized to -1 to indicate no data, but
+  // Pipeline clients should always see a zero value in these cases.

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

In this case, why do we need the concept of "no data"? Can we just make the
default value to be 0?

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

Removed in favor of returning delta stats from renderers.

+  statistics_.audio_memory_usage = 0;
+  statistics_.video_memory_usage = 0;
 }
 
 Pipeline::~Pipeline() {
   DCHECK(thread_checker_.CalledOnValidThread())
       << "Pipeline must be destroyed on same thread that created it";
   DCHECK(!running_) << "Stop() must complete before destroying object";
   DCHECK(stop_cb_.is_null());
   DCHECK(seek_cb_.is_null());
 }
 
@@ skipping 406 matching lines @@
   did_loading_progress_ = true;
 }
 
 // Called from any thread.
 void Pipeline::OnUpdateStatistics(const PipelineStatistics& stats) {
   base::AutoLock auto_lock(lock_);
   statistics_.audio_bytes_decoded += stats.audio_bytes_decoded;
   statistics_.video_bytes_decoded += stats.video_bytes_decoded;
   statistics_.video_frames_decoded += stats.video_frames_decoded;
   statistics_.video_frames_dropped += stats.video_frames_dropped;
+
+  if (stats.audio_memory_usage >= 0)
+    statistics_.audio_memory_usage = stats.audio_memory_usage;
+  if (stats.video_memory_usage >= 0)
+    statistics_.video_memory_usage = stats.video_memory_usage;
 }
 
 void Pipeline::StartTask() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   CHECK_EQ(kCreated, state_)
       << "Media pipeline cannot be started more than once";
 
   text_renderer_ = CreateTextRenderer();
   if (text_renderer_) {
@@ skipping 242 matching lines @@
   metadata_cb_.Run(metadata);
 }
 
 void Pipeline::BufferingStateChanged(BufferingState new_buffering_state) {
   DVLOG(1) << __FUNCTION__ << "(" << new_buffering_state << ") ";
   DCHECK(task_runner_->BelongsToCurrentThread());
   buffering_state_cb_.Run(new_buffering_state);
 }
 
 }  // namespace media