stagefright: don't use ALooperRoster mutex for reply handling

Change replyID-s from uint32_t to an object
Move reply handling into the loopers (to reuse a common mutex)

Bug: 19607784
Change-Id: Iaa035b846c424c5687ed17ce1079b325e86c54be
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
index 126c9f4..452c158 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
@@ -264,7 +264,7 @@
             response->setInt32("err", err);
             response->setInt32("offload", offloadingAudio());
 
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
             response->postReply(replyID);
 
@@ -273,7 +273,7 @@
 
         case kWhatCloseAudioSink:
         {
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
 
             onCloseAudioSink();