Enable renderer side mixing behind a flag.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 885712031913c70f0c3888dfd56d3da018f2766c..d69a24b499ecb67f1c02a8ae618ef1ec1b623946 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -26,6 +26,7 @@
 class AppCacheDispatcher;
 class AudioInputMessageFilter;
 class AudioMessageFilter;
+class AudioRendererMixerManager;
 class CompositorThread;
 class DBMessageFilter;
 class DevToolsAgentFilter;
@@ -223,6 +224,12 @@ class CONTENT_EXPORT RenderThreadImpl : public content::RenderThread,
   // threaded compositing is enabled.
   base::WeakPtr<WebGraphicsContext3DCommandBufferImpl> GetGpuVDAContext3D();
 
+  // Return an AudioRendererMixerManager instance which manages renderer side

[jam, 2012/07/13 15:19:42]

nit: for simple getters like this, the documentation of what the variable does
goes by the member variable (i.e. line 313) and the getter isn't documented

[DaleCurtis, 2012/07/13 21:28:33]

Done.

+  // mixer instances shared based on configured audio parameters.
+  AudioRendererMixerManager* audio_renderer_mixer_manager() {
+    return audio_renderer_mixer_manager_.get();
+  }
+
  private:
   virtual bool OnControlMessageReceived(const IPC::Message& msg) OVERRIDE;
 
@@ -303,6 +310,8 @@ class CONTENT_EXPORT RenderThreadImpl : public content::RenderThread,
 
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> gpu_vda_context3d_;
 
+  scoped_ptr<AudioRendererMixerManager> audio_renderer_mixer_manager_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };