mediaplayer: support dynamic playback rate

Bug: 19196501

Change-Id: I856b1507d5fa2cedfb645706d2435683a7d3e050
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
index abfa4d3..5887e50 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
@@ -341,6 +341,11 @@
     return mState == STATE_RUNNING && !mAtEOS;
 }
 
+status_t NuPlayerDriver::setPlaybackRate(float rate) {
+    mPlayer->setPlaybackRate(rate);
+    return OK;
+}
+
 status_t NuPlayerDriver::seekTo(int msec) {
     ALOGD("seekTo(%p) %d ms", this, msec);
     Mutex::Autolock autoLock(mLock);