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/logging.h"
 #include "base/time/time.h"
 #include "content/renderer/media/webrtc_local_audio_track.h"
 
 using media::AudioBus;
 using media::AudioFifo;
 using media::AudioParameters;
 using media::ChannelLayout;
 using media::CHANNEL_LAYOUT_MONO;
 using media::CHANNEL_LAYOUT_STEREO;
 
 static const int kMaxNumberOfBuffersInFifo = 5;
 
 namespace content {
 
 WebAudioCapturerSource::WebAudioCapturerSource(
-    const blink::WebMediaStreamSource& blink_source)
-    : track_(NULL),
-      audio_format_changed_(false),
-      blink_source_(blink_source) {
+    blink::WebMediaStreamSource* blink_source)
+    : track_(NULL), audio_format_changed_(false), blink_source_(*blink_source) {
+  DCHECK(blink_source);
+  DCHECK(!blink_source_.isNull());
+  DVLOG(1) << "WebAudioCapturerSource::WebAudioCapturerSource()";
+  blink_source_.addAudioConsumer(this);
 }
 
 WebAudioCapturerSource::~WebAudioCapturerSource() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  removeFromBlinkSource();
+  DVLOG(1) << "WebAudioCapturerSource::~WebAudioCapturerSource()";
+  DeregisterFromBlinkSource();
 }
 
 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 28 matching lines @@
   base::AutoLock auto_lock(lock_);
   track_ = track;
 }
 
 void WebAudioCapturerSource::Stop() {
   DCHECK(thread_checker_.CalledOnValidThread());
   {
     base::AutoLock auto_lock(lock_);
     track_ = NULL;
   }
-  // removeFromBlinkSource() should not be called while |lock_| is acquired,
+  // DeregisterFromBlinkSource() should not be called while |lock_| is acquired,
   // as it could result in a deadlock.
-  removeFromBlinkSource();
+  DeregisterFromBlinkSource();
 }
 
 void WebAudioCapturerSource::consumeAudio(
     const blink::WebVector<const float*>& audio_data,
     size_t number_of_frames) {
   base::AutoLock auto_lock(lock_);
   if (!track_)
     return;
 
   // Update the downstream client if the audio format has been changed.
@@ skipping 19 matching lines @@
   }
 
   // Compute the estimated capture time of the first sample frame of audio that
   // will be consumed from the FIFO in the loop below.
   base::TimeTicks estimated_capture_time = base::TimeTicks::Now() -
       fifo_->frames() * base::TimeDelta::FromSeconds(1) / params_.sample_rate();
 
   fifo_->Push(wrapper_bus_.get());
   while (fifo_->frames() >= capture_bus_->frames()) {
     fifo_->Consume(capture_bus_.get(), 0, capture_bus_->frames());
-    track_->Capture(*capture_bus_, estimated_capture_time, false);
+    track_->Capture(*capture_bus_, estimated_capture_time);
 
     // Advance the estimated capture time for the next FIFO consume operation.
     estimated_capture_time +=
         capture_bus_->frames() * base::TimeDelta::FromSeconds(1) /
             params_.sample_rate();
   }
 }
 
-// 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() {
+void WebAudioCapturerSource::DeregisterFromBlinkSource() {
   if (!blink_source_.isNull()) {
     blink_source_.removeAudioConsumer(this);
     blink_source_.reset();
   }
 }
 
 }  // namespace content