Merge changes I52ec5b02,I376656e3,I3f005583,Icba4e33d,I78400f6c, ...
* changes:
Use PassthruPatchRecord for DIRECT to DIRECT connections
Add PassthruPatchRecord for low latency software patches
Abstract access to HAL stream via Source in RecordThread
Move PlaybackThread::Track::writeFrames to PatchRecord
audioflinger: Add tracing of buffer frames to PatchTrack/Record
libaudioprocessing: Extract vendor-available part of AudioMixer
AudioMixer: Cleanups
libaudioprocessing: Trivial dependency cleanups