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/NuPlayerDecoderBase.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerDecoderBase.cpp
index 72e7b0d..a726239 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDecoderBase.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDecoderBase.cpp
@@ -136,7 +136,7 @@
 
         case kWhatGetInputBuffers:
         {
-            uint32_t replyID;
+            sp<AReplyToken> replyID;
             CHECK(msg->senderAwaitsResponse(&replyID));
 
             Vector<sp<ABuffer> > *dstBuffers;