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

Change-Id: Idd5e7ddfa5f2c74e3ffe5ca8c83e4af594b5df14