DO NOT MERGE - improve audio effect framwework thread safety am: 84c392104e  -s ours am: 5d5f9cd28a am: 10f61954ba  -s ours am: bb4c9408ec am: 642e5857fe am: b763905a4f
am: eef8dc0294  -s ours

Change-Id: If09aa28d0491848e7d46cd1543817954935d7e96