audioflinger: Handle pause /resume in stopping state

-Pre-requisite:
 Perform seek on the clip. After seek the data remaining till EOS
 is little more than the driver and common block buffering.
-Framework state:
 Offload thread is waiting for signal from the HAL for a free
 buffer. Audio Player calls sink stop on reaching EOS. Audio
 track is waiting on obtain buffer for a free space in common
 block to send the last buffer. The track is moved to stopping
 state as input EOS is reached.
-Issue:
 Perform pause/ resume in this state(STOPPING), Audio playback
 does not resume.
-Fix
 Ensure resume is called in stopping state if frames ready is
 greater than zero.

Bug: 12870871

Change-Id: Ib1378c4ee5ce4bea655691e93de0775f7b1d2804
Signed-off-by: Glenn Kasten <gkasten@google.com>
diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index b5e763d..e9c6834 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -96,6 +96,8 @@
     void reset();
     bool isFlushPending() const { return mFlushHwPending; }
     void flushAck();
+    bool isResumePending();
+    void resumeAck();
 
     bool isOutputTrack() const {
         return (mStreamType == AUDIO_STREAM_CNT);