Squashed commit of the following:

commit 63be8ceb8b2354fb997a277c0092abae015ecf10
Author: Andreas Huber <andih@google.com>
Date:   Fri Dec 17 13:45:34 2010 -0800

    Enable handling of discontinuities that involve potential format changes.

    Change-Id: I21848a113db8764abb54bdcf302b0923253eaf4d

commit d18a7f80ec09af382026809263dcbbfa9e7a9ec8
Author: Andreas Huber <andih@google.com>
Date:   Fri Dec 17 13:45:01 2010 -0800

    Signal whether or not a format change occured as part of the discontinuity.

    Change-Id: I06e64f542f4369549c9cebbb892dc612346ae43d

commit c400adbd5fdbd65cfef7aed9ec65bcaace4bb69b
Author: Andreas Huber <andih@google.com>
Date:   Fri Dec 17 13:44:46 2010 -0800

    A little more instrumentation of ACodec

    Change-Id: I07f4aeccbbd15cdd9f80f48c3f92ee984ef6d92b

commit 1d802ee01f47b3cdc5b89502cec7fbb595e197a3
Author: Andreas Huber <andih@google.com>
Date:   Fri Dec 17 13:43:58 2010 -0800

    Only sync audio/video queues if both types of media are actually present.

    Change-Id: Ic88edf9bb1ebd4034c08747cce9877a4e28e0d35

commit e402da39d9a4d8b75653a78f728e20a3ef0fb497
Author: Andreas Huber <andih@google.com>
Date:   Fri Dec 17 13:42:24 2010 -0800

    Disable the random seek for now.

    Change-Id: Iddd597b546e2f229e88214f9bdd6452bb188105e

Change-Id: I27c4d9ba916080be94ce6117dbb095e9022ed62b
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
index 834ddc5..eaa004a 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
@@ -37,6 +37,8 @@
 
     void signalTimeDiscontinuity();
 
+    void signalAudioSinkChanged();
+
     enum {
         kWhatEOS,
         kWhatFlushComplete,
@@ -54,6 +56,7 @@
         kWhatQueueBuffer,
         kWhatQueueEOS,
         kWhatFlush,
+        kWhatAudioSinkChanged,
     };
 
     struct QueueEntry {
@@ -81,6 +84,8 @@
     bool mFlushingAudio;
     bool mFlushingVideo;
 
+    bool mHasAudio;
+    bool mHasVideo;
     bool mSyncQueues;
 
     void onDrainAudioQueue();
@@ -92,6 +97,7 @@
     void onQueueBuffer(const sp<AMessage> &msg);
     void onQueueEOS(const sp<AMessage> &msg);
     void onFlush(const sp<AMessage> &msg);
+    void onAudioSinkChanged();
 
     void notifyEOS(bool audio);
     void notifyFlushComplete(bool audio);