libmediaplayerservice: get isStreaming info from source.

Bug: 19061436
Change-Id: I0fc0d6207b0d3297d64aadab3e81448e3f3fa1de
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.cpp b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
index 88a7745..8ec542a 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
@@ -324,6 +324,10 @@
     return INVALID_OPERATION;
 }
 
+bool NuPlayer::GenericSource::isStreaming() const {
+    return mIsStreaming;
+}
+
 NuPlayer::GenericSource::~GenericSource() {
     if (mLooper != NULL) {
         mLooper->unregisterHandler(id());