This interface will be improved upon iteratively to aid reviewability. The initial version only handles starting and stopping the module; input and output of the module is still implementation-specific. TBR=sprang@webrtc.org Bug: webrtc:11222 Change-Id: Ie307cfe3d3211c84346c035f2c0e9a632f58221b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162580 Commit-Queue: Henrik Boström <hbos@webrtc.org> Reviewed-by: Evan Shrubsole <eshr@google.com> Cr-Commit-Position: refs/heads/master@{#30167}