Revert of MediaStream audio object graph untangling and clean-ups.

content/renderer/media/webaudio_capturer_source.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 "content/renderer/media/webaudio_capturer_source.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "content/renderer/media/webrtc_local_audio_track.h"
 
 using media::AudioBus;
 using media::AudioParameters;
 using media::ChannelLayout;
 using media::CHANNEL_LAYOUT_MONO;
 using media::CHANNEL_LAYOUT_STEREO;
 
 namespace content {
 
 WebAudioCapturerSource::WebAudioCapturerSource(
-    blink::WebMediaStreamSource* blink_source)
+    const blink::WebMediaStreamSource& blink_source)
     : track_(NULL),
       audio_format_changed_(false),
       fifo_(base::Bind(&WebAudioCapturerSource::DeliverRebufferedAudio,
                        base::Unretained(this))),
-      blink_source_(*blink_source) {
-  DCHECK(blink_source);
-  DCHECK(!blink_source_.isNull());
-  DVLOG(1) << "WebAudioCapturerSource::WebAudioCapturerSource()";
-  blink_source_.addAudioConsumer(this);
-}
+      blink_source_(blink_source) {}
 
 WebAudioCapturerSource::~WebAudioCapturerSource() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  DVLOG(1) << "WebAudioCapturerSource::~WebAudioCapturerSource()";
-  DeregisterFromBlinkSource();
+  removeFromBlinkSource();
 }
 
 void WebAudioCapturerSource::setFormat(
     size_t number_of_channels, float sample_rate) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DVLOG(1) << "WebAudioCapturerSource::setFormat(sample_rate="
            << sample_rate << ")";
 
   // If the channel count is greater than 8, use discrete layout. However,
   // anything beyond 8 is ignored by the subsequent (WebRTC) audio pipeline.
@@ skipping 27 matching lines @@
   base::AutoLock auto_lock(lock_);
   track_ = track;
 }
 
 void WebAudioCapturerSource::Stop() {
   DCHECK(thread_checker_.CalledOnValidThread());
   {
     base::AutoLock auto_lock(lock_);
     track_ = NULL;
   }
-  // DeregisterFromBlinkSource() should not be called while |lock_| is acquired,
+  // removeFromBlinkSource() should not be called while |lock_| is acquired,
   // as it could result in a deadlock.
-  DeregisterFromBlinkSource();
+  removeFromBlinkSource();
 }
 
 void WebAudioCapturerSource::consumeAudio(
     const blink::WebVector<const float*>& audio_data,
     size_t number_of_frames) {
   // TODO(miu): Plumbing is needed to determine the actual capture timestamp
   // of the audio, instead of just snapshotting TimeTicks::Now(), for proper
   // audio/video sync.  http://crbug.com/335335
   current_reference_time_ = base::TimeTicks::Now();
 
@@ skipping 19 matching lines @@
 
 void WebAudioCapturerSource::DeliverRebufferedAudio(
     const media::AudioBus& audio_bus,
     int frame_delay) {
   lock_.AssertAcquired();
   const base::TimeTicks reference_time =
       current_reference_time_ +
       base::TimeDelta::FromMicroseconds(frame_delay *
                                         base::Time::kMicrosecondsPerSecond /
                                         params_.sample_rate());
-  track_->Capture(audio_bus, reference_time);
+  track_->Capture(audio_bus, reference_time, false);
 }
 
-void WebAudioCapturerSource::DeregisterFromBlinkSource() {
+// If registered as audio consumer in |blink_source_|, deregister from
+// |blink_source_| and stop keeping a reference to |blink_source_|.
+// Failure to call this method when stopping the track might leave an invalid
+// WebAudioCapturerSource reference still registered as an audio consumer on
+// the blink side.
+void WebAudioCapturerSource::removeFromBlinkSource() {
   if (!blink_source_.isNull()) {
     blink_source_.removeAudioConsumer(this);
     blink_source_.reset();
   }
 }
 
 }  // namespace content