Do not spam "Connect failed with 101/65" in logs.

webrtc/base/network.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 821 matching lines @@
   std::unique_ptr<AsyncSocket> socket(
       thread_->socketserver()->CreateAsyncSocket(family, SOCK_DGRAM));
   if (!socket) {
     LOG_ERR(LERROR) << "Socket creation failed";
     return IPAddress();
   }
 
   if (socket->Connect(SocketAddress(
           family == AF_INET ? kPublicIPv4Host : kPublicIPv6Host, kPublicPort)) <
       0) {
-    LOG(LS_INFO) << "Connect failed with " << socket->GetError();
+    if (socket->GetError() != ENETUNREACH

[honghaiz3, 2016/09/28 19:36:30]

Should we log an error message if the query for both IPv4 and IPv6 failed?
That might provide some meaningful information when debugging networking issues.

[skvlad, 2016/09/28 21:22:54]

This would have to be elsewhere in NetworkManager - probably done only once
instead of every N seconds. The message I'm silencing wasn't useful for that as
it didn't say which of the two interfaces were unreachable - one (which is
expected) or both (which isn't).

[honghaiz3, 2016/09/28 21:33:05]

Agree that can be done in a separate CL. Perhaps add a TODO here and/or file a
bug for that. 

[skvlad, 2016/09/28 22:27:46]

Filed https://bugs.chromium.org/p/webrtc/issues/detail?id=6438.

+        && socket->GetError() != EHOSTUNREACH) {
+      // Ignore the expected case of "host/net unreachable" - which happens if
+      // the network is V4- or V6-only.
+      LOG(LS_INFO) << "Connect failed with " << socket->GetError();
+    }
     return IPAddress();
   }
   return socket->GetLocalAddress().ipaddr();
 }
 
 void BasicNetworkManager::UpdateNetworksOnce() {
   if (!start_count_)
     return;
 
   ASSERT(Thread::Current() == thread_);
@@ skipping 123 matching lines @@
   std::stringstream ss;
   // Print out the first space-terminated token of the network desc, plus
   // the IP address.
   ss << "Net[" << description_.substr(0, description_.find(' '))
      << ":" << prefix_.ToSensitiveString() << "/" << prefix_length_
      << ":" << AdapterTypeToString(type_) << "]";
   return ss.str();
 }
 
 }  // namespace rtc