Add AudioStreamRegistry. Move stream counting logic

content/browser/renderer_host/media/audio_output_delegate.cc

Index: content/browser/renderer_host/media/audio_output_delegate.cc
diff --git a/content/browser/renderer_host/media/audio_output_delegate.cc b/content/browser/renderer_host/media/audio_output_delegate.cc
index 32d936eb3f69ad35c575347c5cc2584cddbdb736..eec4e48fc5c77de56c457760d94b2e38c444d072 100644
--- a/content/browser/renderer_host/media/audio_output_delegate.cc
+++ b/content/browser/renderer_host/media/audio_output_delegate.cc
@@ -18,6 +18,7 @@ namespace content {
 
 AudioOutputDelegate::AudioOutputDelegate(
     EventHandler* handler,
+    AudioStreamRegistry* stream_registry,
     media::AudioManager* audio_manager,
     std::unique_ptr<media::AudioLog> audio_log,
     int stream_id,
@@ -26,6 +27,7 @@ AudioOutputDelegate::AudioOutputDelegate(
     const media::AudioParameters& params,
     const std::string& output_device_id)
     : handler_(handler),
+      stream_registry_(stream_registry),
       audio_log_(std::move(audio_log)),
       reader_(AudioSyncReader::Create(params)),
       stream_id_(stream_id),
@@ -37,6 +39,7 @@ AudioOutputDelegate::AudioOutputDelegate(
   DCHECK(audio_log_);
   weak_this_ = weak_factory_.GetWeakPtr();
   audio_log_->OnCreated(stream_id, params, output_device_id);
+  stream_registry->RegisterOutputStream(this);
   controller_ = media::AudioOutputController::Create(
       audio_manager, this, params, output_device_id, reader_.get());
   DCHECK(controller_);
@@ -51,6 +54,7 @@ AudioOutputDelegate::~AudioOutputDelegate() {
 void AudioOutputDelegate::Deleter::operator()(AudioOutputDelegate* delegate) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   delegate->UpdatePlayingState(false);
+  delegate->stream_registry_->DeregisterOutputStream(delegate);
   delegate->handler_ = nullptr;
   delegate->audio_log_->OnClosed(delegate->stream_id_);
 
@@ -82,6 +86,7 @@ void AudioOutputDelegate::Deleter::operator()(AudioOutputDelegate* delegate) {
 // static
 AudioOutputDelegate::UniquePtr AudioOutputDelegate::Create(
     EventHandler* handler,
+    AudioStreamRegistry* stream_registry,
     media::AudioManager* audio_manager,
     std::unique_ptr<media::AudioLog> audio_log,
     AudioMirroringManager* mirroring_manager,
@@ -94,9 +99,9 @@ AudioOutputDelegate::UniquePtr AudioOutputDelegate::Create(
   if (media_observer)
     media_observer->OnCreatingAudioStream(render_process_id, render_frame_id);
   UniquePtr delegate(
-      new AudioOutputDelegate(handler, audio_manager, std::move(audio_log),
-                              stream_id, render_frame_id, render_process_id,
-                              params, output_device_id),
+      new AudioOutputDelegate(handler, stream_registry, audio_manager,
+                              std::move(audio_log), stream_id, render_frame_id,
+                              render_process_id, params, output_device_id),
       Deleter(mirroring_manager));
   if (mirroring_manager)
     mirroring_manager->AddDiverter(render_process_id, render_frame_id,
@@ -162,7 +167,7 @@ void AudioOutputDelegate::UpdatePlayingState(bool playing) {
     return;
 
   playing_ = playing;
-  handler_->OnStreamStateChanged(playing);
+  stream_registry_->OutputStreamStateChanged(playing);
   if (playing) {
     // Note that this takes a reference to |controller_|, and
     // (Start|Stop)MonitoringStream calls are async, so we don't have a