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

Change-Id: I9b07b232e0cdccdf7e9b21ebaa3073839eb8e882