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

content/renderer/media/webrtc/mock_peer_connection_dependency_factory.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h"
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/renderer/media/mock_peer_connection_impl.h"
 #include "content/renderer/media/webaudio_capturer_source.h"
@@ skipping 386 matching lines @@
 };
 
 class MockIceCandidate : public IceCandidateInterface {
  public:
   MockIceCandidate(const std::string& sdp_mid,
                    int sdp_mline_index,
                    const std::string& sdp)
       : 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 {
     return sdp_mid_;
   }
   virtual int sdp_mline_index() const OVERRIDE {
     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_;
     return true;
   }
 
  private:
   std::string sdp_mid_;
   int sdp_mline_index_;
   std::string sdp_;
+  cricket::Candidate candidate_;
 };
 
 MockPeerConnectionDependencyFactory::MockPeerConnectionDependencyFactory()
     : PeerConnectionDependencyFactory(NULL),
       fail_to_create_next_audio_capturer_(false) {
 }
 
 MockPeerConnectionDependencyFactory::~MockPeerConnectionDependencyFactory() {}
 
 scoped_refptr<webrtc::PeerConnectionInterface>
@@ skipping 91 matching lines @@
   return WebRtcAudioCapturer::CreateCapturer(-1, device_info,
                                              constraints, NULL, audio_source);
 }
 
 void MockPeerConnectionDependencyFactory::StartLocalAudioTrack(
       WebRtcLocalAudioTrack* audio_track) {
   audio_track->Start();
 }
 
 }  // namespace content