We use Optional in our public API, so its header should be in
webrtc/api/.
BUG=webrtc:8205
Review-Url: https://codereview.webrtc.org/3011943002
Cr-Commit-Position: refs/heads/master@{#19693}
SrtpTransportInterface methods take cricket::CryptoParams, so this
should be enough for now.
BUG=webrtc:7311
Review-Url: https://codereview.webrtc.org/2753343002
Cr-Commit-Position: refs/heads/master@{#17299}