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 am: 7454e9d217 am: 5acee4ff97
am: e5de51e57c

Change-Id: Ie4260a73818c13ed183b6191c29cc10e9a120d2f