MediaSync: add getTimestamp in MediaSync.

Bug: 19666434
Change-Id: Ieae70b13864e3eb5abae3577f209f4b926418731
diff --git a/media/jni/android_media_MediaSync.h b/media/jni/android_media_MediaSync.h
index 5750083..976a456 100644
--- a/media/jni/android_media_MediaSync.h
+++ b/media/jni/android_media_MediaSync.h
@@ -25,6 +25,7 @@
 
 class AudioTrack;
 struct IGraphicBufferProducer;
+struct MediaClock;
 class MediaSync;
 
 struct JMediaSync : public RefBase {
@@ -40,6 +41,8 @@
 
     void setPlaybackRate(float rate);
 
+    sp<const MediaClock> getMediaClock();
+
 protected:
     virtual ~JMediaSync();