Add network_type to local RTCIceCandidateStats

Details:
  * Add RTCNetworkType enum
  * Add network_type to local ice candidate stats

Bug: webrtc:8435
Change-Id: Idb872849c09ad49c8f759d02afdc825e397afa07
Reviewed-on: https://webrtc-review.googlesource.com/14680
Commit-Queue: Gary Liu <qinghualiu@google.com>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20822}
diff --git a/pc/rtcstats_integrationtest.cc b/pc/rtcstats_integrationtest.cc
index d0a5863..b6c92f3 100644
--- a/pc/rtcstats_integrationtest.cc
+++ b/pc/rtcstats_integrationtest.cc
@@ -463,6 +463,11 @@
     verifier.TestMemberIsIDReference(
         candidate.transport_id, RTCTransportStats::kType);
     verifier.TestMemberIsDefined(candidate.is_remote);
+    if (*candidate.is_remote) {
+      verifier.TestMemberIsUndefined(candidate.network_type);
+    } else {
+      verifier.TestMemberIsDefined(candidate.network_type);
+    }
     verifier.TestMemberIsDefined(candidate.ip);
     verifier.TestMemberIsNonNegative<int32_t>(candidate.port);
     verifier.TestMemberIsDefined(candidate.protocol);