DO NOT MERGE - improve audio effect framwework thread safety am: b47a5ab107 am: 26cf2f4d73 am: 73a152960b  -s ours am: 21d6eafd26  -s ours am: 6c5deab4f2 am: 9685820100  -s ours am: 6608eddab9 am: c6a7a42379
am: d1b6293802

Change-Id: Iec2ba59fd23c72b83efd444bba0e1024109b627c