Reason for revert: Broke browser_tests on Mac. Still need to investigate the cause. Original issue's description: > Moving MediaStreamSignaling logic into PeerConnection. > > This needs to happen because in the future, m-lines will be offered > based on the set of RtpSenders/RtpReceivers, rather than the set of > tracks that MediaStreamSignaling knows about. > > Besides that, MediaStreamSignaling was a "glue class" without > a clearly defined role, so it going away is good for other > reasons as well. > > Committed: https://crrev.com/97c392935411398b506861601c82e31d95c591f0 > Cr-Commit-Position: refs/heads/master@{#10268} TBR=pthatcher@webrtc.org NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true Review URL: https://codereview.webrtc.org/1403633005 Cr-Commit-Position: refs/heads/master@{#10269}