These interfaces will be used by the future refactoring that will
allow clients to provide custom codec implementations.
Change-Id: If199bc2807e1c27094c05983c62fa43d2eec5700
Bug: webrtc:7760
Reviewed-on: https://chromium-review.googlesource.com/522065
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Bjorn Mellem <mellem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18441}
e2410e9ab4