Part 2: Plumb render view ID to content::MediaObserver

content/public/browser/media_observer.h

Index: content/public/browser/media_observer.h
diff --git a/content/public/browser/media_observer.h b/content/public/browser/media_observer.h
index f7ae0dce3547048fa00a84bfcf4a7b4e3ca80c9c..225bf761aa7e047473a65166d62b3f073fb978ff 100644
--- a/content/public/browser/media_observer.h
+++ b/content/public/browser/media_observer.h
@@ -18,19 +18,27 @@ namespace content {
 class MediaObserver {
  public:
   // Called when an audio stream is deleted.
-  virtual void OnDeleteAudioStream(void* host, int stream_id) = 0;
+  virtual void OnDeleteAudioStream(int render_process_id,
+                                   int render_view_id,
+                                   int stream_id) = 0;
 
   // Called when an audio stream is set to playing or paused.
-  virtual void OnSetAudioStreamPlaying(void* host, int stream_id,
+  virtual void OnSetAudioStreamPlaying(int render_process_id,
+                                       int render_view_id,
+                                       int stream_id,
                                        bool playing) = 0;
 
   // Called when the status of an audio stream is set to "created", "flushed",
   // "closed", or "error".
-  virtual void OnSetAudioStreamStatus(void* host, int stream_id,
+  virtual void OnSetAudioStreamStatus(int render_process_id,
+                                      int render_view_id,
+                                      int stream_id,
                                       const std::string& status) = 0;
 
   // Called when the volume of an audio stream is set.
-  virtual void OnSetAudioStreamVolume(void* host, int stream_id,
+  virtual void OnSetAudioStreamVolume(int render_process_id,
+                                      int render_view_id,
+                                      int stream_id,
                                       double volume) = 0;
 
   // Called when a MediaEvent occurs.