This CL adds tracking and reporting of packet feedback availability in
the VideoSendStream class.
This is part of a series of CLs tracking the transport feedback status
of the streams known to BitrateAllocator and reporting the status to
the congestion controller.
Bug: webrtc:8415
Change-Id: I4e7b6d5b034b4ae1e86ea439e6d001eea04784ce
Reviewed-on: https://webrtc-review.googlesource.com/63204
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22545}
ccd1523be4