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

content/browser/renderer_host/media/audio_renderer_host.h

 // 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.
 //
 // AudioRendererHost serves audio related requests from AudioRenderer which
 // lives inside the render process and provide access to audio hardware.
 //
 // This class is owned by BrowserRenderProcessHost, and instantiated on UI
 // thread, but all other operations and method calls happen on IO thread, so we
 // need to be extra careful about the lifetime of this object. AudioManager is a
@@ skipping 58 matching lines @@
   struct AudioEntry {
     AudioEntry();
     ~AudioEntry();
 
     // The AudioOutputController that manages the audio stream.
     scoped_refptr<media::AudioOutputController> controller;
 
     // The audio stream ID.
     int stream_id;
 
+    // The render view ID.
+    int render_view_id;
+
     // Shared memory for transmission of the audio data.
     base::SharedMemory shared_memory;
 
     // The synchronous reader to be used by the controller. We have the
     // ownership of the reader.
     scoped_ptr<media::AudioOutputController::SyncReader> reader;
 
     // Set to true after we called Close() for the controller.
     bool pending_close;
   };
 
   typedef std::map<int, AudioEntry*> AudioEntryMap;
 
   // Called from UI thread from the owner of this object.
-  AudioRendererHost(media::AudioManager* audio_manager,
+  AudioRendererHost(int render_process_id,
+                    media::AudioManager* audio_manager,
                     content::MediaObserver* media_observer);
 
   // content::BrowserMessageFilter implementation.
   virtual void OnChannelClosing() OVERRIDE;
   virtual void OnDestruct() const OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
 
   // AudioOutputController::EventHandler implementations.
   virtual void OnCreated(media::AudioOutputController* controller) OVERRIDE;
@@ skipping 67 matching lines @@
 
   // A helper method to look up a AudioEntry identified by |stream_id|.
   // Returns NULL if not found.
   AudioEntry* LookupById(int stream_id);
 
   // Search for a AudioEntry having the reference to |controller|.
   // This method is used to look up an AudioEntry after a controller
   // event is received.
   AudioEntry* LookupByController(media::AudioOutputController* controller);
 
+  int render_process_id_;
+
   // A map of stream IDs to audio sources.
   AudioEntryMap audio_entries_;
 
   media::AudioManager* audio_manager_;
   content::MediaObserver* media_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererHost);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_