Replacing SSLIdentity* with scoped_refptr<RTCCertificate> in TransportDescriptionFactory layer

talk/app/webrtc/webrtcsessiondescriptionfactory.cc

Index: talk/app/webrtc/webrtcsessiondescriptionfactory.cc
diff --git a/talk/app/webrtc/webrtcsessiondescriptionfactory.cc b/talk/app/webrtc/webrtcsessiondescriptionfactory.cc
index 41bcfa0593688b0911a6d53f53cfdc0206d04288..a06437f33452337188b16d716447724371435001 100644
--- a/talk/app/webrtc/webrtcsessiondescriptionfactory.cc
+++ b/talk/app/webrtc/webrtcsessiondescriptionfactory.cc
@@ -255,7 +255,7 @@ WebRtcSessionDescriptionFactory::~WebRtcSessionDescriptionFactory() {
     }
   }
 
-  transport_desc_factory_.set_identity(NULL);
+  transport_desc_factory_.set_certificate(nullptr);
 }
 
 void WebRtcSessionDescriptionFactory::CreateOffer(
@@ -522,8 +522,7 @@ void WebRtcSessionDescriptionFactory::SetCertificate(
   certificate_request_state_ = CERTIFICATE_SUCCEEDED;
   SignalCertificateReady(certificate);
 
-  // TODO(hbos): set_certificate
-  transport_desc_factory_.set_identity(certificate->identity());
+  transport_desc_factory_.set_certificate(certificate);
   transport_desc_factory_.set_secure(cricket::SEC_ENABLED);
 
   while (!create_session_description_requests_.empty()) {