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 dcebdee53e48828842b0d8929a2a780e77c69311..08f5ce6e7b9abd25dfa758487afa5144d23428b7 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -188,7 +188,7 @@ 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;
   }