7af91ddd6b
"Crypto required" is a property of the PeerConnection of construction time; it has nothing to do with SDP. So I'm moving it out of MediaContentDescription and putting it in the BaseChannel constructor instead. This is more intuitive, and provides the added assurance that "secure_required_" can't be flipped from "true" to "false". BUG=None Review-Url: https://codereview.webrtc.org/2537343003 Cr-Commit-Position: refs/heads/master@{#15579}