Add Cronet experimental option to disable ipv6

net/dns/mapped_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/mapped_host_resolver.h"
 
 #include <utility>
 
 #include "base/strings/string_util.h"
 #include "base/values.h"
@@ skipping 38 matching lines @@
 }
 
 HostCache* MappedHostResolver::GetHostCache() {
   return impl_->GetHostCache();
 }
 
 std::unique_ptr<base::Value> MappedHostResolver::GetDnsConfigAsValue() const {
   return impl_->GetDnsConfigAsValue();
 }
 
+void MappedHostResolver::SetDefaultAddressFamily(AddressFamily address_family) {

[xunjieli, 2017/02/27 15:37:39]

Is this needed? Cronet only use mapped host resolver in testing. You did not add
an integration/java test, so i assume this is not strictly necessary.

[mgersh, 2017/02/28 18:29:57]

It's needed for the unit test to work the way it's currently structured. I could
structure it differently but this seems more useful.

+  impl_->SetDefaultAddressFamily(address_family);
+}
+
+AddressFamily MappedHostResolver::GetDefaultAddressFamily() const {
+  return impl_->GetDefaultAddressFamily();
+}
+
 int MappedHostResolver::ApplyRules(RequestInfo* info) const {
   HostPortPair host_port(info->host_port_pair());
   if (rules_.RewriteHost(&host_port)) {
     if (host_port.host() == "~NOTFOUND")
       return ERR_NAME_NOT_RESOLVED;
     info->set_host_port_pair(host_port);
   }
   return OK;
 }
 
 }  // namespace net