RTCIceCandidatePairStats.[total/current]RoundTripTime collected.

webrtc/p2p/base/port.cc

Index: webrtc/p2p/base/port.cc
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
index bf57cf956815dc1fafe6f1c7cd8d490e82a431d5..c4d797d2bd850027a205e2b03c86bf06e1b04829 100644
--- a/webrtc/p2p/base/port.cc
+++ b/webrtc/p2p/base/port.cc
@@ -1251,6 +1251,7 @@ void Connection::ReceivedPing() {
 }
 
 void Connection::ReceivedPingResponse(int rtt, const std::string& request_id) {
+  RTC_DCHECK_GE(rtt, 0);
   // We've already validated that this is a STUN binding response with
   // the correct local and remote username for this connection.
   // So if we're not already, become writable. We may be bringing a pruned
@@ -1264,6 +1265,16 @@ void Connection::ReceivedPingResponse(int rtt, const std::string& request_id) {
     acked_nomination_ = iter->nomination;
   }
 
+  current_round_trip_time_ms_ = rtc::Optional<uint32_t>(
+      static_cast<uint32_t>(rtt));
+  if (!total_round_trip_time_ms_) {
+    total_round_trip_time_ms_ = rtc::Optional<uint64_t>(
+        static_cast<uint64_t>(rtt));
+  } else {
+    total_round_trip_time_ms_ = rtc::Optional<uint64_t>(
+        *total_round_trip_time_ms_ + rtt);
+  }
+
   pings_since_last_response_.clear();
   last_ping_response_received_ = rtc::TimeMillis();
   UpdateReceiving(last_ping_response_received_);
@@ -1503,6 +1514,8 @@ ConnectionInfo Connection::stats() {
   stats_.key = this;
   stats_.state = state_;
   stats_.priority = priority();
+  stats_.total_round_trip_time_ms = total_round_trip_time_ms_;
+  stats_.current_round_trip_time_ms = current_round_trip_time_ms_;
   return stats_;
 }