Disable IPv6 results for the PAC bindings:...

net/proxy/proxy_resolver_js_bindings.cc

Index: net/proxy/proxy_resolver_js_bindings.cc
===================================================================
--- net/proxy/proxy_resolver_js_bindings.cc	(revision 29678)
+++ net/proxy/proxy_resolver_js_bindings.cc	(working copy)
@@ -32,9 +32,12 @@
   }
 
   // Run the resolve on host_resolver_loop, and wait for result.
-  int Resolve(const std::string& hostname, net::AddressList* addresses) {
+  int Resolve(const std::string& hostname,
+              AddressFamily address_family,
+              net::AddressList* addresses) {
     // Port number doesn't matter.
     HostResolver::RequestInfo info(hostname, 80);
+    info.set_address_family(address_family);
 
     // Hack for tests -- run synchronously on current thread.
     if (!host_resolver_loop_)
@@ -107,8 +110,11 @@
       return std::string();
 
     // Do a sync resolve of the hostname.
+    // Disable IPv6 results, see http://crbug.com/24641 for motivation.

[wtc, 2009/10/22 21:53:54]

The motivation is short (dnsResolve is IPv4 only).  I'd just
state it here rather than forcing the reader to read a long
bug report.

     net::AddressList address_list;
-    int result = host_resolver_->Resolve(host, &address_list);
+    int result = host_resolver_->Resolve(host,
+                                         ADDRESS_FAMILY_IPV4_ONLY,

[wtc, 2009/10/22 21:53:54]

Nit: do we really need _ONLY in the enum constant name?

Except for ADDRESS_FAMILY_UNSPECIFIED, all the
ADDRESS_FAMILY_ enum constants specify a single address
family.  So _ONLY is implied.

+                                         &address_list);
 
     if (result != OK)
       return std::string();  // Failed.