Add Stats to Stun ping.

webrtc/api/statstypes.cc

Index: webrtc/api/statstypes.cc
diff --git a/webrtc/api/statstypes.cc b/webrtc/api/statstypes.cc
index 61af82467a7595b2ff255726bd2d53a334839fa5..9e5e176d822961b477ec2c1e5344fcdb7e560a5d 100644
--- a/webrtc/api/statstypes.cc
+++ b/webrtc/api/statstypes.cc
@@ -414,6 +414,18 @@ const char* StatsReport::Value::display_name() const {
       return "googBucketDelay";
     case kStatsValueNameBandwidthLimitedResolution:
       return "googBandwidthLimitedResolution";
+    // STUN ping related attributes.
+    // TODO(zhihuang) Rename these stats to follow the standards.
+    case kStatsValueNameSentPingRequestsTotal:
+      return "requestsSent";
+    case kStatsValueNameSentPingRequestsBeforeFirstResponse:
+      return "consentRequestsSent";
+    case kStatsValueNameSentPingResponses:
+      return "responsesSent";
+    case kStatsValueNameRecvPingRequests:
+      return "requestsReceived";
+    case kStatsValueNameRecvPingResponses:
+      return "responsesReceived";
 
     // Candidate related attributes. Values are taken from
     // http://w3c.github.io/webrtc-stats/#rtcstatstype-enum*.