This meant splitting "transport_options" into audio/video/data options, for when creating the answer, and giving "GetSslRole" a "transport_name" parameter so we can retrieve the current role on a per-transport basis. BUG=webrtc:4525 R=pthatcher@webrtc.org Review URL: https://codereview.webrtc.org/1516993002 . Cr-Commit-Position: refs/heads/master@{#11192}