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..3d9a515cff2bf342cd578c70fba4a30a181cacb3 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -36,6 +36,15 @@ namespace cricket {
 
 extern const uint32_t WEAK_PING_DELAY;
 
+struct IceGeneration {

[pthatcher1, 2015/12/10 22:08:06]

Now that I see the code, I see that it gets confusing that "generation"
sometimes means "generation index" and other times means "generation
credentials".  So perhaps we should just keep generation as "index" and instead
call this "IceParameters"

[honghaiz3, 2015/12/11 04:47:29]

Done.

+  std::string ufrag;
+  std::string pwd;
+  IceGeneration(const std::string& ice_ufrag, const std::string& ice_pwd) {

[pthatcher1, 2015/12/10 22:08:06]

Could be:

IceGenration(const std::string& ufrag, const std::string& pwd) : ufrag(ufrag),
pwd(pwd) {}

[honghaiz3, 2015/12/11 04:47:29]

Done.

+    ufrag = ice_ufrag;
+    pwd = ice_pwd;
+  }
+};
+
 // Adds the port on which the candidate originated.
 class RemoteCandidate : public Candidate {
  public:
@@ -229,6 +238,21 @@ class P2PTransportChannel : public TransportChannelImpl,
   Connection* best_nominated_connection() const;
   bool IsBackupConnection(Connection* conn) const;
 
+  // Makes sure |remote_ice_generations_| is not empty before calling this.
+  std::string& remote_ice_ufrag() {
+    ASSERT(!remote_ice_generations_.empty());
+    return remote_ice_generations_.back().ufrag;
+  }
+  // Makes sure |remote_ice_generations_| is not empty before calling this.
+  std::string& remote_ice_pwd() {
+    ASSERT(!remote_ice_generations_.empty());
+    return remote_ice_generations_.back().pwd;
+  }

[pthatcher1, 2015/12/10 22:08:06]

I think it would be better to have a remote_ice() getter that returns an
Optional<IceParameters>.  See how it could be used in the next file.

[honghaiz3, 2015/12/11 04:47:29]

Done.

+  int remote_ice_generation() {
+    // When |remote_ice_generations_| has one element, it is generation 0.
+    return remote_ice_generations_.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<IceGeneration> remote_ice_generations_;

[pthatcher1, 2015/12/10 22:08:06]

And remote_ice_parameters_ might make sense here.

[honghaiz3, 2015/12/11 04:47:29]

Done.

   IceMode remote_ice_mode_;
   IceRole ice_role_;
   uint64_t tiebreaker_;
-  uint32_t remote_candidate_generation_;
   IceGatheringState gathering_state_;
 
   int check_receiving_delay_;