[net/dns] Resolve AF_UNSPEC on dual-stacked systems. Sort addresses according to RFC3484.

net/base/host_resolver_impl.h

Index: net/base/host_resolver_impl.h
diff --git a/net/base/host_resolver_impl.h b/net/base/host_resolver_impl.h
index 8c2579d8705fb71bacdc6683a2b025ba3ebf1037..fa62cce8dc4a8adc478e47b8c91b86067ebfb3d2 100644
--- a/net/base/host_resolver_impl.h
+++ b/net/base/host_resolver_impl.h
@@ -19,14 +19,17 @@
 #include "net/base/host_resolver.h"
 #include "net/base/host_resolver_proc.h"
 #include "net/base/net_export.h"
-#include "net/base/net_log.h"
 #include "net/base/network_change_notifier.h"
 #include "net/base/prioritized_dispatcher.h"
-#include "net/dns/dns_client.h"
-#include "net/dns/dns_config_service.h"
 
 namespace net {
 
+class BoundNetLog;
+class DnsClient;
+struct DnsConfig;
+class DnsConfigService;
+class NetLog;
+
 // For each hostname that is requested, HostResolver creates a
 // HostResolverImpl::Job. When this job gets dispatched it creates a ProcTask
 // which runs the given HostResolverProc on a WorkerPool thread. If requests for