Add two UMA counters for IPv4 and IPv6 local candidates gathered in WebRTC PeerConnection.

content/renderer/media/rtc_peer_connection_handler.cc

Index: content/renderer/media/rtc_peer_connection_handler.cc
diff --git a/content/renderer/media/rtc_peer_connection_handler.cc b/content/renderer/media/rtc_peer_connection_handler.cc
index c5c68e4d7418ba6b9d591e72cfbb5fd56e2e8657..70755bd6f42d78f085fda61a2fa41d84ea611a8a 100644
--- a/content/renderer/media/rtc_peer_connection_handler.cc
+++ b/content/renderer/media/rtc_peer_connection_handler.cc
@@ -390,7 +390,9 @@ RTCPeerConnectionHandler::RTCPeerConnectionHandler(
       dependency_factory_(dependency_factory),
       frame_(NULL),
       peer_connection_tracker_(NULL),
-      num_data_channels_created_(0) {
+      num_data_channels_created_(0),
+      num_local_candidates_ipv4_(0),
+      num_local_candidates_ipv6_(0) {
   g_peer_connection_handlers.Get().insert(this);
 }
 
@@ -894,6 +896,12 @@ void RTCPeerConnectionHandler::OnIceGatheringChange(
     // to signal end of candidates.
     blink::WebRTCICECandidate null_candidate;
     client_->didGenerateICECandidate(null_candidate);
+
+    UMA_HISTOGRAM_COUNTS_100("WebRTC.PeerConnection.IPv4LocalCandidates",
+                             num_local_candidates_ipv4_);
+
+    UMA_HISTOGRAM_COUNTS_100("WebRTC.PeerConnection.IPv6LocalCandidates",
+                             num_local_candidates_ipv6_);
   }
 
   blink::WebRTCPeerConnectionHandlerClient::ICEGatheringState state =
@@ -968,6 +976,14 @@ void RTCPeerConnectionHandler::OnIceCandidate(
     peer_connection_tracker_->TrackAddIceCandidate(
         this, web_candidate, PeerConnectionTracker::SOURCE_LOCAL, true);
 
+  if (candidate->candidate().address().family() == AF_INET) {
+    num_local_candidates_ipv4_++;
+  } else if (candidate->candidate().address().family() == AF_INET6) {
+    num_local_candidates_ipv6_++;
+  } else {
+    NOTREACHED();
+  }
+
   client_->didGenerateICECandidate(web_candidate);
 }