8a855d6916
The first unsignalled SSRC creates a default receive channel. Any unsignalled SSRC changes after that replace the default SSRC. Add unit tests for changing unsignalled SSRCs. BUG=webrtc:5208 Review-Url: https://codereview.webrtc.org/2692993009 Cr-Commit-Position: refs/heads/master@{#16682}