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..54c20b3a5028a8fa6bfc802f6bad645959edf108 100644
--- a/webrtc/p2p/base/transportdescription.h
+++ b/webrtc/p2p/base/transportdescription.h
@@ -60,11 +60,30 @@ enum ConnectionRole {
   CONNECTIONROLE_HOLDCONN,
 };
 
+struct IceParameters {
+  std::string ufrag;
+  std::string pwd;
+  bool renomination;

[Taylor Brandstetter, 2016/08/08 22:28:16]

Why not have "renomination = false" here and then use a default constructor
("IceParameters() = default;") below?

[honghaiz3, 2016/08/11 04:57:57]

Done. Thanks!

+  IceParameters() : renomination(false) {}
+  IceParameters(const std::string& ice_ufrag,
+                const std::string& ice_pwd,
+                bool ice_renomination)
+      : ufrag(ice_ufrag), pwd(ice_pwd), renomination(ice_renomination) {}

[Taylor Brandstetter, 2016/08/08 22:28:16]

nit: The "ice_" prefix in the names seems redundant, since it's an IceParameters
struct.

[honghaiz3, 2016/08/11 04:57:57]

I generally prefer that the parameter names are different from the member
variables to avoid potential confusion and shadowing, even though there is no
immediate problem here. 

[Taylor Brandstetter, 2016/08/11 22:36:50]

Acknowledged; that's a fair point.

[honghaiz3, 2016/08/12 18:26:40]

Acknowledged.

+
+  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 +144,10 @@ 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)