Always treat .localhost as loopback

net/base/net_util.h

 // Copyright (c) 2012 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_NET_UTIL_H_
 #define NET_BASE_NET_UTIL_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
@@ skipping 423 matching lines @@
                                            socklen_t address_len);
 
 // Returns true if |host| is one of the names (e.g. "localhost") or IP
 // addresses (IPv4 127.0.0.0/8 or IPv6 ::1) that indicate a loopback.
 //
 // Note that this function does not check for IP addresses other than
 // the above, although other IP addresses may point to the local
 // machine.
 NET_EXPORT_PRIVATE bool IsLocalhost(const std::string& host);
 
+NET_EXPORT_PRIVATE bool IsLocalhostTLD(const std::string& host);
+
 // A subset of IP address attributes which are actionable by the
 // application layer. Currently unimplemented for all hosts;
 // IP_ADDRESS_ATTRIBUTE_NONE is always returned.
 enum IPAddressAttributes {
   IP_ADDRESS_ATTRIBUTE_NONE = 0,
 
   // A temporary address is dynamic by nature and will not contain MAC
   // address. Presence of MAC address in IPv6 addresses can be used to
   // track an endpoint and cause privacy concern. Please refer to
   // RFC4941.
@@ skipping 124 matching lines @@
   DSCP_CS5  = 40,  // Video
   DSCP_EF   = 46,  // Voice
   DSCP_CS6  = 48,  // Voice
   DSCP_CS7  = 56,  // Control messages
   DSCP_LAST = DSCP_CS7
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NET_UTIL_H_