Remove candidates when doing continual gathering

webrtc/api/webrtcsdp.cc

Index: webrtc/api/webrtcsdp.cc
diff --git a/webrtc/api/webrtcsdp.cc b/webrtc/api/webrtcsdp.cc
index a6edf7ce187d9fa4d9e8e55f25465703b3a3e6c2..6bab4076cab9e42da60e8cf7447c9164eccda4e6 100644
--- a/webrtc/api/webrtcsdp.cc
+++ b/webrtc/api/webrtcsdp.cc
@@ -154,8 +154,7 @@ static const char kValueConference[] = "conference";
 // Candidate
 static const char kCandidateHost[] = "host";
 static const char kCandidateSrflx[] = "srflx";
-// TODO: How to map the prflx with circket candidate type
-// static const char kCandidatePrflx[] = "prflx";
+static const char kCandidatePrflx[] = "prflx";
 static const char kCandidateRelay[] = "relay";
 static const char kTcpCandidateType[] = "tcptype";
 
@@ -1014,6 +1013,8 @@ bool ParseCandidate(const std::string& message, Candidate* candidate,
     candidate_type = cricket::STUN_PORT_TYPE;
   } else if (type == kCandidateRelay) {
     candidate_type = cricket::RELAY_PORT_TYPE;
+  } else if (type == kCandidatePrflx) {
+    candidate_type = cricket::PRFLX_PORT_TYPE;
   } else {
     return ParseFailed(first_line, "Unsupported candidate type.", error);
   }
@@ -1752,6 +1753,9 @@ void BuildCandidate(const std::vector<Candidate>& candidates,
       type = kCandidateSrflx;
     } else if (it->type() == cricket::RELAY_PORT_TYPE) {
       type = kCandidateRelay;
+    } else if (it->type() == cricket::PRFLX_PORT_TYPE) {
+      type = kCandidatePrflx;
+      // Peer reflexive candidate may be signaled for being removed.
     } else {
       ASSERT(false);
       // Never write out candidates if we don't know the type.