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/NuPlayer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
index 007fbb9..f4d3794 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
@@ -408,7 +408,7 @@
 
         case kWhatGetTrackInfo:
         {
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
 
             Parcel* reply;
@@ -461,7 +461,7 @@
             sp<AMessage> response = new AMessage;
             response->setInt32("err", err);
 
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
             response->postReply(replyID);
             break;
@@ -469,7 +469,7 @@
 
         case kWhatSelectTrack:
         {
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
 
             size_t trackIndex;