Change WebRTC SslCipher to be exposed as number only.

webrtc/p2p/base/faketransportcontroller.h

Index: webrtc/p2p/base/faketransportcontroller.h
diff --git a/webrtc/p2p/base/faketransportcontroller.h b/webrtc/p2p/base/faketransportcontroller.h
index e356e814b754a1b2b6f88f987b7bd33cb46e943a..a6af1937c67ac859006d4c15171d370015e6d3c6 100644
--- a/webrtc/p2p/base/faketransportcontroller.h
+++ b/webrtc/p2p/base/faketransportcontroller.h
@@ -249,7 +249,7 @@ 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 {
     return local_cert_;