Groundwork to support bidirectional, asynchronous communication

between NuPlayer and its sources.

Change-Id: I1989022d806206b926555add3aa5c1fcf37aa78d
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayer.h b/media/libmediaplayerservice/nuplayer/NuPlayer.h
index 09fc0ba..0ff6089 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.h
@@ -95,6 +95,7 @@
         kWhatPause                      = 'paus',
         kWhatResume                     = 'rsme',
         kWhatPollDuration               = 'polD',
+        kWhatSourceNotify               = 'srcN',
     };
 
     wp<NuPlayerDriver> mDriver;