Add CryptoParams to webrtc::MediaSession.

SrtpTransportInterface methods take cricket::CryptoParams, so this
should be enough for now.

BUG=webrtc:7311

Review-Url: https://codereview.webrtc.org/2753343002
Cr-Original-Commit-Position: refs/heads/master@{#17299}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 7aeabd081f148e489d1e9d360c3fe7587a92b606
2 files changed