[Linux] Enable connecting to localhost when offline.

net/base/host_resolver_impl.h

 // Copyright (c) 2010 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.
 
 #ifndef NET_BASE_HOST_RESOLVER_IMPL_H_
 #define NET_BASE_HOST_RESOLVER_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 234 matching lines @@
   bool shutdown_;
 
   // Indicate if probing is done after each network change event to set address
   // family.
   // When false, explicit setting of address family is used.
   bool ipv6_probe_monitoring_;
 
   // The last un-cancelled IPv6ProbeJob (if any).
   scoped_refptr<IPv6ProbeJob> ipv6_probe_job_;
 
+  // Any resolver flags that should be added to a request by default.
+  HostResolverFlags additional_resolver_flags_;
+
   DISALLOW_COPY_AND_ASSIGN(HostResolverImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_HOST_RESOLVER_IMPL_H_