Remove StartSSLWithServer from SSLStreamAdapter.

It's not used by anything any more. We only use SSLStreamAdapter in
the mode where it verifies the peer's certificate using a signaled
digest.

R=pthatcher@webrtc.org, zhihuang@webrtc.org

Review URL: https://codereview.webrtc.org/2204883004 .

Cr-Original-Commit-Position: refs/heads/master@{#13730}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: c8762a838f6d21377ef8fa2e4642b464e3347545
6 files changed