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

Counter will be accumulated for each OnIceCandidate callback and report once the IceGathering is completed.

BUG=411086

Review URL: https://codereview.chromium.org/600163004

Cr-Commit-Position: refs/heads/master@{#296965}

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 +896,18 @@ 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_);
+  } else if (new_state ==
+             webrtc::PeerConnectionInterface::kIceGatheringGathering) {
+    // ICE restarts will change gathering state back to "gathering",
+    // reset the counter.
+    num_local_candidates_ipv6_ = 0;
+    num_local_candidates_ipv4_ = 0;
   }
 
   blink::WebRTCPeerConnectionHandlerClient::ICEGatheringState state =
@@ -968,6 +982,18 @@ void RTCPeerConnectionHandler::OnIceCandidate(
     peer_connection_tracker_->TrackAddIceCandidate(
         this, web_candidate, PeerConnectionTracker::SOURCE_LOCAL, true);
 
+  // Only the first m line's first component is tracked to avoid
+  // miscounting when doing BUNDLE or rtcp mux.
+  if (candidate->sdp_mline_index() == 0 &&
+      candidate->candidate().component() == 1) {
+    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);
 }
 

content/renderer/media/rtc_peer_connection_handler.h

@@ -218,6 +218,10 @@ class CONTENT_EXPORT RTCPeerConnectionHandler
   // Counter for a UMA stat reported at destruction time.
   int num_data_channels_created_;
 
+  // Counter for number of IPv4 and IPv6 local candidates.
+  int num_local_candidates_ipv4_;
+  int num_local_candidates_ipv6_;
+
   // |native_peer_connection_| is the libjingle native PeerConnection object.
   scoped_refptr<webrtc::PeerConnectionInterface> native_peer_connection_;
 

content/renderer/media/webrtc/mock_peer_connection_dependency_factory.cc

@@ -404,6 +404,8 @@ class MockIceCandidate : public IceCandidateInterface {
       : sdp_mid_(sdp_mid),
         sdp_mline_index_(sdp_mline_index),
         sdp_(sdp) {
+    // Assign an valid address to |candidate_| to pass assert in code.
+    candidate_.set_address(rtc::SocketAddress("127.0.0.1", 5000));
   }
   virtual ~MockIceCandidate() {}
   virtual std::string sdp_mid() const OVERRIDE {
@@ -413,11 +415,7 @@ class MockIceCandidate : public IceCandidateInterface {
     return sdp_mline_index_;
   }
   virtual const cricket::Candidate& candidate() const OVERRIDE {
-    // This function should never be called. It will intentionally crash. The
-    // base class forces us to return a reference.
-    NOTREACHED();
-    cricket::Candidate* candidate = NULL;
-    return *candidate;
+    return candidate_;
   }
   virtual bool ToString(std::string* out) const OVERRIDE {
     *out = sdp_;
@@ -428,6 +426,7 @@ class MockIceCandidate : public IceCandidateInterface {
   std::string sdp_mid_;
   int sdp_mline_index_;
   std::string sdp_;
+  cricket::Candidate candidate_;
 };
 
 MockPeerConnectionDependencyFactory::MockPeerConnectionDependencyFactory()

tools/metrics/histograms/histograms.xml

@@ -37971,6 +37971,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="WebRTC.PeerConnection.IPv4LocalCandidates">
+  <owner>guoweis@chromium.org</owner>
+  <summary>
+    Number of IPv4 local Candidates gathered in a PeerConnection Session once
+    the ICE address gathering process reaches the Completed status. To avoid
+    miscounting, this only includes the first m line's first component.
+  </summary>
+</histogram>
+
 <histogram name="WebRTC.PeerConnection.IPv6Interfaces">
   <owner>mallinath@chromium.org</owner>
   <summary>
@@ -37978,6 +37987,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="WebRTC.PeerConnection.IPv6LocalCandidates">
+  <owner>guoweis@chromium.org</owner>
+  <summary>
+    Number of IPv6 local Candidates gathered in a PeerConnection Session once
+    the ICE address gathering process reaches the Completed status. To avoid
+    miscounting, this only includes the first m line's first component.
+  </summary>
+</histogram>
+
 <histogram name="WebRTC.PeerConnection.TimeToConnect" units="milliseconds">
   <owner>mallinath@chromium.org</owner>
   <summary>Time to setup a peer to peer call with PeerConnection.</summary>