Change WebRTC SslCipher to be exposed as number only.

webrtc/p2p/base/dtlstransportchannel.cc

Index: webrtc/p2p/base/dtlstransportchannel.cc
diff --git a/webrtc/p2p/base/dtlstransportchannel.cc b/webrtc/p2p/base/dtlstransportchannel.cc
index b434d0860e1e73763a89d1fddbc2439d39fd5c4f..b17140f2581e4ebcb65c4e5f2204d766582ceb82 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -186,7 +186,7 @@ bool DtlsTransportChannelWrapper::GetSslRole(rtc::SSLRole* role) const {
   return true;
 }
 
-bool DtlsTransportChannelWrapper::GetSslCipher(std::string* cipher) {
+bool DtlsTransportChannelWrapper::GetSslCipher(rtc::SslCipher* cipher) {
   if (dtls_state_ != STATE_OPEN) {
     return false;
   }