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..59629596cce0e0a514b09982d8fa2bbe2a959a4e 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(uint16_t* cipher) override { return false; }
 
   rtc::scoped_refptr<rtc::RTCCertificate> GetLocalCertificate() const {
     return local_cert_;