Plumb render view ID from audio-related code in renderer through IPCs to AudioRendererHost in brows…

content/renderer/media/audio_renderer_mixer_manager.cc

Index: content/renderer/media/audio_renderer_mixer_manager.cc
diff --git a/content/renderer/media/audio_renderer_mixer_manager.cc b/content/renderer/media/audio_renderer_mixer_manager.cc
index 411ae8b430a346e647f51e447faeaee20bdc7694..1a485215280c76fb2342e7f3de4757c58b6f31bd 100644
--- a/content/renderer/media/audio_renderer_mixer_manager.cc
+++ b/content/renderer/media/audio_renderer_mixer_manager.cc
@@ -22,20 +22,24 @@ AudioRendererMixerManager::~AudioRendererMixerManager() {
   DCHECK(mixers_.empty());
 }
 
-media::AudioRendererMixerInput* AudioRendererMixerManager::CreateInput() {
+media::AudioRendererMixerInput* AudioRendererMixerManager::CreateInput(
+    int render_view_id) {
   return new media::AudioRendererMixerInput(
       base::Bind(
-          &AudioRendererMixerManager::GetMixer, base::Unretained(this)),
+          &AudioRendererMixerManager::GetMixer, base::Unretained(this),
+          render_view_id),
       base::Bind(
-          &AudioRendererMixerManager::RemoveMixer, base::Unretained(this)));
+          &AudioRendererMixerManager::RemoveMixer, base::Unretained(this),
+          render_view_id));
 }
 
 media::AudioRendererMixer* AudioRendererMixerManager::GetMixer(
-    const media::AudioParameters& params) {
+    int render_view_id, const media::AudioParameters& params) {
   base::AutoLock auto_lock(mixers_lock_);
 
-  AudioRendererMixerMap::iterator it = mixers_.find(params);
-  if (it != mixers_.end()) {
+  MixerByParamsMap& mixers_by_params = mixers_[render_view_id];
+  MixerByParamsMap::iterator it = mixers_by_params.find(params);
+  if (it != mixers_by_params.end()) {
     it->second.ref_count++;
     return it->second.mixer;
   }
@@ -48,25 +52,32 @@ media::AudioRendererMixer* AudioRendererMixerManager::GetMixer(
       hardware_sample_rate_, 16, hardware_buffer_size_);
 
   media::AudioRendererMixer* mixer = new media::AudioRendererMixer(
-      params, output_params, AudioDeviceFactory::NewOutputDevice());
+      params, output_params,
+      AudioDeviceFactory::NewOutputDevice(render_view_id));
 
   AudioRendererMixerReference mixer_reference = { mixer, 1 };
-  mixers_[params] = mixer_reference;
+  mixers_by_params[params] = mixer_reference;
   return mixer;
 }
 
 void AudioRendererMixerManager::RemoveMixer(
-    const media::AudioParameters& params) {
+    int render_view_id, const media::AudioParameters& params) {
   base::AutoLock auto_lock(mixers_lock_);
 
-  AudioRendererMixerMap::iterator it = mixers_.find(params);
-  DCHECK(it != mixers_.end());
+  AudioRendererMixerMap::iterator mixers_it = mixers_.find(render_view_id);
+  DCHECK(mixers_it != mixers_.end());
+  MixerByParamsMap& mixers_by_params = mixers_it->second;
+  MixerByParamsMap::iterator it = mixers_by_params.find(params);
+  DCHECK(it != mixers_by_params.end());
 
   // Only remove the mixer if AudioRendererMixerManager is the last owner.
   it->second.ref_count--;
   if (it->second.ref_count == 0) {
     delete it->second.mixer;
-    mixers_.erase(it);
+    mixers_by_params.erase(it);
+    if (mixers_by_params.empty()) {
+      mixers_.erase(mixers_it);
+    }
   }
 }