DO NOT MERGE - improve audio effect framwework thread safety am: 7da83aadf4 am: 5717bb1acb  -s ours am: 199484a558 am: fff4a6aff9 am: c8fbf1a97c
am: 8e24a55a3c  -s ours

Change-Id: Ib577ae77e113b8c0a545ae40fa6d00abbc614f1b