Change WebRTC SslCipher to be exposed as number only.

webrtc/p2p/base/fakesession.h

Index: webrtc/p2p/base/fakesession.h
diff --git a/webrtc/p2p/base/fakesession.h b/webrtc/p2p/base/fakesession.h
index bd3c08902508fafc1cf414db3fecbb2d141e48bf..22c8203b713844e42d11e0c36e8ccfec2bd96685 100644
--- a/webrtc/p2p/base/fakesession.h
+++ b/webrtc/p2p/base/fakesession.h
@@ -246,9 +246,7 @@ class FakeTransportChannel : public TransportChannelImpl,
     return false;
   }
 
-  bool GetSslCipher(std::string* cipher) override {
-    return false;
-  }
+  bool GetSslCipher(rtc::SslCipher* cipher) override { return false; }
 
   rtc::scoped_refptr<rtc::RTCCertificate>
   GetLocalCertificate() const override {