Plumb render view ID to media observer

content/renderer/media/audio_renderer_mixer_manager.h

Index: content/renderer/media/audio_renderer_mixer_manager.h
diff --git a/content/renderer/media/audio_renderer_mixer_manager.h b/content/renderer/media/audio_renderer_mixer_manager.h
index ab713f96a078f0df88c85807fa09fb4dabe5fed8..2ed54392717fdd0f77e3e418f873a17e7f97f3e0 100644
--- a/content/renderer/media/audio_renderer_mixer_manager.h
+++ b/content/renderer/media/audio_renderer_mixer_manager.h
@@ -18,6 +18,8 @@ class AudioRendererMixerInput;
 
 namespace content {
 
+class RenderView;
+
 // Manages sharing of an AudioRendererMixer among AudioRendererMixerInputs based
 // on their AudioParameters configuration.  Inputs with the same AudioParameters
 // configuration will share a mixer while a new AudioRendererMixer will be
@@ -40,14 +42,15 @@ class CONTENT_EXPORT AudioRendererMixerManager {
   // Creates an AudioRendererMixerInput with the proper callbacks necessary to
   // retrieve an AudioRendererMixer instance from AudioRendererMixerManager.
   // Caller must ensure AudioRendererMixerManager outlives the returned input.
-  media::AudioRendererMixerInput* CreateInput();
+  media::AudioRendererMixerInput* CreateInput(RenderView* render_view);
 
  private:
   friend class AudioRendererMixerManagerTest;
 
   // Returns a mixer instance based on AudioParameters; an existing one if one
   // with the provided AudioParameters exists or a new one if not.
-  media::AudioRendererMixer* GetMixer(const media::AudioParameters& params);
+  media::AudioRendererMixer* GetMixer(RenderView* render_view,
+                                      const media::AudioParameters& params);
 
   // Remove a mixer instance given a mixer if the only other reference is held
   // by AudioRendererMixerManager.  Every AudioRendererMixer owner must call