This CL interfaces the SDP information (payload types and
SSRCs) about FlexFEC with the corresponding configs at the
Call layer. It also adds a field trial, which when active
will expose FlexFEC in the default codec list, thus showing
up in the default SDP.
BUG=webrtc:5654
R=magjed@webrtc.org, stefan@webrtc.orgCC=perkj@webrtc.org
Review-Url: https://codereview.webrtc.org/2511703002
Cr-Commit-Position: refs/heads/master@{#15184}
468da7c074