Added a callback to signal when the rendering of the video frame just occurred

Change-Id: Ifbd78606ffc33483aecebf02cb18e0e52af9624d
related-to-bug: 6851811
diff --git a/include/media/mediaplayer.h b/include/media/mediaplayer.h
index 1fad383..f7cebc5 100644
--- a/include/media/mediaplayer.h
+++ b/include/media/mediaplayer.h
@@ -99,6 +99,8 @@
     // The player was started because it was used as the next player for another
     // player, which just completed playback
     MEDIA_INFO_STARTED_AS_NEXT = 2,
+    // The player just pushed the very first video frame for rendering
+    MEDIA_INFO_RENDERING_START = 3,
     // 7xx
     // The video is too complex for the decoder: it can't decode frames fast
     // enough. Possibly only the audio plays fine at this stage.