91540aeb6c
This is not a real race, because addOutputTrack was only called in two places, and in both places there could be no other threads referencing the DuplicatingThread instance. Those two places are: - the DuplicatingThread constructor, which is of course safe - openDuplicateOutput - this is safe because it's called immediately after the new DuplicatingThread, and there are no sp<> either in the constructor or here which could cause onFirstRef() to do Thread::run(). But for safety in case addOutputTrack is ever called somewhere else, or there are sp<> created earlier, it is safer to take the thread lock. Change-Id: I1502d014fa37ec5dbf4bf40d3e2884af311cd5e9