There are 2 ways to design this. 1. TCP Only mode: this means that we disable all UDP protocols across board. 2. disallow TURN over UDP. Along with DISABLE_UDP, DISABLE_STUN, we should achieve the same result. I'm going with #2. BUG=webrtc:4784 R=pthatcher@webrtc.org Review URL: https://codereview.webrtc.org/1311153003 . Cr-Commit-Position: refs/heads/master@{#9791}