This CL changes the auto-pause logic to suspend a stream based on the
encoder target bitrate instead of the allocated bitrate for a stream,
to account for possible protection, e.g. FEC and NACK.
This CL also adds periodic logging of the current BWE and possibility
to run with suspension in video loopback test.
BUG=webrtc:5868
R=stefan@webrtc.org
Review URL: https://codereview.webrtc.org/2117493002 .
Cr-Commit-Position: refs/heads/master@{#13360}
48a4beb7a4