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 am: 76f5a383ea am: 6e300c3a99 am: 99b29882e4 am: 0b59c76959 am: 5f4aace8cd
am: 91e1787e6c  -s ours

Change-Id: Ia280c126e9e6c34e527c1d30adf4666c61973a8b