CmaMediaPipelineClient to watch media pipeline status

chromecast/browser/media/cma_message_filter_host.h

Index: chromecast/browser/media/cma_message_filter_host.h
diff --git a/chromecast/browser/media/cma_message_filter_host.h b/chromecast/browser/media/cma_message_filter_host.h
index 6408ba4d21f2bd8cfca35da4d2db8e7394d99483..28ac7ad1fb6aecd90c2942125dbc8151b6fc9caf 100644
--- a/chromecast/browser/media/cma_message_filter_host.h
+++ b/chromecast/browser/media/cma_message_filter_host.h
@@ -50,7 +50,9 @@ class CmaMessageFilterHost
 
   CmaMessageFilterHost(
       int render_process_id,
-      const CreateDeviceComponentsCB& create_device_components_cb);
+      const CreateDeviceComponentsCB& create_device_components_cb,
+      const base::Closure& on_device_components_create_cb,
+      const base::Closure& on_device_components_destroy_cb);

[halliwell, 2015/08/25 00:48:34]

I think we should replace 'device components' with 'pipeline backend' in this
class - it's old terminology now (MediaPipelineBackend class used to be called
something like DeviceComponents).

[yucliu1, 2015/08/25 04:27:58]

Done.

 
   // content::BrowserMessageFilter implementation.
   void OnChannelClosing() override;
@@ -120,6 +122,9 @@ class CmaMessageFilterHost
 
   // Factory function for device-specific part of media pipeline creation
   CreateDeviceComponentsCB create_device_components_cb_;
+  // Callbacks for device components' create and destroy

[halliwell, 2015/08/25 00:48:34]

nit: creation, destruction

[yucliu1, 2015/08/25 04:27:58]

Done.

+  base::Closure on_device_components_create_cb_;
+  base::Closure on_device_components_destroy_cb_;
 
   // List of media pipeline and message loop media pipelines are running on.
   MediaPipelineMap media_pipelines_;