DO NOT MERGE - improve audio effect framwework thread safety am: b47a5ab107 am: 26cf2f4d73 am: 73a152960b  -s ours am: 21d6eafd26  -s ours
am: 6c5deab4f2

Change-Id: I680ead77538594903bc5140f68eeb920a7ac39c0