Revert "Add back "default address family" to HostResolver"

net/dns/host_resolver.cc

 // 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.
 
 #include "net/dns/host_resolver.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 114 matching lines @@
 }
 
 std::unique_ptr<base::Value> HostResolver::GetDnsConfigAsValue() const {
   return nullptr;
 }
 
 void HostResolver::InitializePersistence(
     const PersistCallback& persist_callback,
     std::unique_ptr<const base::Value> old_data) {}
 
-void HostResolver::SetDefaultAddressFamily(AddressFamily address_family) {
-  NOTREACHED();
-}
-
-AddressFamily HostResolver::GetDefaultAddressFamily() const {
-  return ADDRESS_FAMILY_UNSPECIFIED;
-}
-
 void HostResolver::SetNoIPv6OnWifi(bool no_ipv6_on_wifi) {
   NOTREACHED();
 }
 
 bool HostResolver::GetNoIPv6OnWifi() {
   return false;
 }
 
 // static
 std::unique_ptr<HostResolver> HostResolver::CreateSystemResolver(
@@ skipping 18 matching lines @@
 
 // static
 std::unique_ptr<HostResolverImpl> HostResolver::CreateDefaultResolverImpl(
     NetLog* net_log) {
   return CreateSystemResolverImpl(Options(), net_log);
 }
 
 HostResolver::HostResolver() {}
 
 }  // namespace net