Tab Audio Capture: Browser-side connect/disconnect functionality.

content/browser/renderer_host/media/audio_renderer_host.h

Index: content/browser/renderer_host/media/audio_renderer_host.h
diff --git a/content/browser/renderer_host/media/audio_renderer_host.h b/content/browser/renderer_host/media/audio_renderer_host.h
index 43e9395ac50ff90293b55f24cda1c8a1e59c78cf..a02eeca9cffe1d970cce885014426c8ad003aa92 100644
--- a/content/browser/renderer_host/media/audio_renderer_host.h
+++ b/content/browser/renderer_host/media/audio_renderer_host.h
@@ -61,13 +61,15 @@ namespace content {
 
 class MediaObserver;
 class ResourceContext;
+class WebContentsAudioInputStream;
 
 class CONTENT_EXPORT AudioRendererHost
     : public BrowserMessageFilter,
       public media::AudioOutputController::EventHandler {
  public:
   // Called from UI thread from the owner of this object.
-  AudioRendererHost(media::AudioManager* audio_manager,
+  AudioRendererHost(int render_process_id,
+                    media::AudioManager* audio_manager,
                     MediaObserver* media_observer);
 
   // BrowserMessageFilter implementation.
@@ -83,6 +85,17 @@ class CONTENT_EXPORT AudioRendererHost
   virtual void OnError(media::AudioOutputController* controller,
                        int error_code) OVERRIDE;
 
+  // Start/stop mirroring all audio output streams associated with
+  // |render_view_id| to |destination|.
+  void StartMirroring(int render_view_id,
+                      WebContentsAudioInputStream* destination);
+  void StopMirroring(int render_view_id,

[Alpha Left Google, 2012/11/20 21:49:43]

Does a destination associate with multiple render view? If not can this just
take |destination|?

[miu, 2012/11/21 08:27:48]

I thought about this, and I don't think I needed the 2nd argument.

However, after resolving the WCAIS threading issue, I do need to pass
destination in a scoped_refptr to make sure a reference is held on |destination|
until the IO thread removes all the streams from it.  (This all might be easier
to discuss in-person tomorrow.)

+                     WebContentsAudioInputStream* destination);
+
+  // Return the AudioRendererHost instance for a render process.
+  static scoped_refptr<AudioRendererHost> FromRenderProcessID(
+      int render_process_id);
+
  private:
   friend class AudioRendererHostTest;
   friend class BrowserThread;
@@ -94,6 +107,8 @@ class CONTENT_EXPORT AudioRendererHost
   struct AudioEntry;
   typedef std::map<int, AudioEntry*> AudioEntryMap;
 
+  typedef std::map<int, WebContentsAudioInputStream*> MirrorSessionMap;
+
   virtual ~AudioRendererHost();
 
   // Methods called on IO thread ----------------------------------------------
@@ -106,6 +121,10 @@ class CONTENT_EXPORT AudioRendererHost
                       const media::AudioParameters& params,
                       int input_channels);
 
+  // Associate |render_view_id| as the producer of audio for the stream
+  // referenced by |stream_id|.
+  void OnAssociateStreamWithProducer(int stream_id, int render_view_id);
+
   // Play the audio stream referenced by |stream_id|.
   void OnPlayStream(int stream_id);
 
@@ -160,9 +179,15 @@ class CONTENT_EXPORT AudioRendererHost
 
   media::AudioOutputController* LookupControllerByIdForTesting(int stream_id);
 
+  // ID of the RenderProcessImpl that owns this instance.
+  const int render_process_id_;
+
   // A map of stream IDs to audio sources.
   AudioEntryMap audio_entries_;
 
+  // A map of render view IDs to the destination for active mirroring sessions.
+  MirrorSessionMap mirror_sessions_;
+
   media::AudioManager* audio_manager_;
   MediaObserver* media_observer_;