Add signaling to support ICE renomination.

webrtc/p2p/base/transportdescription.h

Index: webrtc/p2p/base/transportdescription.h
diff --git a/webrtc/p2p/base/transportdescription.h b/webrtc/p2p/base/transportdescription.h
index 42e45a670f9f415331466e76d1742b67f54d64b9..df8ee92003ef88af0b0d1f76de0a7256517e0781 100644
--- a/webrtc/p2p/base/transportdescription.h
+++ b/webrtc/p2p/base/transportdescription.h
@@ -60,11 +60,33 @@ enum ConnectionRole {
   CONNECTIONROLE_HOLDCONN,
 };
 
+struct IceParameters {
+  // TODO(honghaiz): Include ICE mode in this structure to match the ORTC
+  // struct:
+  // http://ortc.org/wp-content/uploads/2016/03/ortc.html#idl-def-RTCIceParameters
+  std::string ufrag;
+  std::string pwd;
+  bool renomination = false;
+  IceParameters() = default;
+  IceParameters(const std::string& ice_ufrag,
+                const std::string& ice_pwd,
+                bool ice_renomination)
+      : ufrag(ice_ufrag), pwd(ice_pwd), renomination(ice_renomination) {}
+
+  bool operator==(const IceParameters& other) {
+    return ufrag == other.ufrag && pwd == other.pwd &&
+           renomination == other.renomination;
+  }
+  bool operator!=(const IceParameters& other) { return !(*this == other); }
+};
+
 extern const char CONNECTIONROLE_ACTIVE_STR[];
 extern const char CONNECTIONROLE_PASSIVE_STR[];
 extern const char CONNECTIONROLE_ACTPASS_STR[];
 extern const char CONNECTIONROLE_HOLDCONN_STR[];
 
+constexpr auto ICE_RENOMINATION_STR = "renomination";
+
 bool StringToConnectionRole(const std::string& role_str, ConnectionRole* role);
 bool ConnectionRoleToString(const ConnectionRole& role, std::string* role_str);
 
@@ -125,6 +147,10 @@ struct TransportDescription {
   }
   bool secure() const { return identity_fingerprint != NULL; }
 
+  IceParameters GetIceParameters() {
+    return IceParameters(ice_ufrag, ice_pwd, HasOption(ICE_RENOMINATION_STR));
+  }
+
   static rtc::SSLFingerprint* CopyFingerprint(
       const rtc::SSLFingerprint* from) {
     if (!from)