Add ufrag to the ICE candidate signaling.

webrtc/p2p/base/p2ptransportchannel.h

Index: webrtc/p2p/base/p2ptransportchannel.h
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
index 2b02d36a61ab899d3dc462982ac4d39f35faea41..5c7d33cd452b20456ce51c44eecfff50c9fc507e 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -30,12 +30,24 @@
 #include "webrtc/p2p/base/transport.h"
 #include "webrtc/p2p/base/transportchannelimpl.h"
 #include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/optional.h"
 #include "webrtc/base/sigslot.h"
 
 namespace cricket {
 
 extern const uint32_t WEAK_PING_DELAY;
 
+struct IceParameter {

[pthatcher1, 2015/12/12 00:30:34]

IceParameters

(with an "s")

Yes, I know that makes ice_parameters_ a little weird, but I think that's OK.

[honghaiz3, 2015/12/14 18:40:19]

Done.

+  std::string ufrag;
+  std::string pwd;
+  IceParameter(const std::string& ice_ufrag, const std::string& ice_pwd)
+      : ufrag(ice_ufrag), pwd(ice_pwd) {}
+  IceParameter() : ufrag(""), pwd("") {}
+  bool operator!=(const IceParameter& other) {

[pthatcher1, 2015/12/12 00:30:34]

Can you implement both == and != just to make sure we don't mess up some logic
where we use one instead of the other?

[honghaiz3, 2015/12/14 18:40:19]

Done.

+    return ufrag != other.ufrag || pwd != other.pwd;
+  }
+};
+
 // Adds the port on which the candidate originated.
 class RemoteCandidate : public Candidate {
  public:
@@ -229,6 +241,18 @@ class P2PTransportChannel : public TransportChannelImpl,
   Connection* best_nominated_connection() const;
   bool IsBackupConnection(Connection* conn) const;
 
+  rtc::Optional<IceParameter> remote_ice() {

[pthatcher1, 2015/12/12 00:30:34]

Can you leave a comment saying it's the latest remote ice parameters?

[honghaiz3, 2015/12/14 18:40:19]

Done.

+    return remote_ice_parameters_.empty()
+               ? rtc::Optional<IceParameter>()
+               : rtc::Optional<IceParameter>(remote_ice_parameters_.back());
+  }

[pthatcher1, 2015/12/12 00:30:34]

If it's too much of a problem to avoid copying with an Optional, we could just
return a IceParameter*:

return remote_ice_parameters_.empty() ? nullptr :
&remote_ice_parameters_.back();

[honghaiz3, 2015/12/14 18:40:19]

Done.

+  uint32_t remote_ice_generation() {

[pthatcher1, 2015/12/12 00:30:34]

Can you leave a comment saying it's the index of the latest remote ice
parameters, or 0 if there are none?

[honghaiz3, 2015/12/14 18:40:19]

Done.

+    // When |remote_ice_parameters_| has one element, it is generation 0.
+    return remote_ice_parameters_.empty()
+               ? 0
+               : static_cast<uint32_t>(remote_ice_parameters_.size() - 1);
+  }
+
   P2PTransport* transport_;
   PortAllocator* allocator_;
   rtc::Thread* worker_thread_;
@@ -248,12 +272,10 @@ class P2PTransportChannel : public TransportChannelImpl,
   OptionMap options_;
   std::string ice_ufrag_;
   std::string ice_pwd_;
-  std::string remote_ice_ufrag_;
-  std::string remote_ice_pwd_;
+  std::vector<IceParameter> remote_ice_parameters_;
   IceMode remote_ice_mode_;
   IceRole ice_role_;
   uint64_t tiebreaker_;
-  uint32_t remote_candidate_generation_;
   IceGatheringState gathering_state_;
 
   int check_receiving_delay_;