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

net/dns/dns_client.h

Index: net/dns/dns_client.h
diff --git a/net/dns/dns_client.h b/net/dns/dns_client.h
index 13aa0bf8ed1183320180b4482110a15540df6e93..07407f0279cc13023e06aa667ab062253080702c 100644
--- a/net/dns/dns_client.h
+++ b/net/dns/dns_client.h
@@ -10,6 +10,7 @@
 
 namespace net {
 
+class AddressSorter;
 struct DnsConfig;
 class DnsTransactionFactory;
 class NetLog;
@@ -29,6 +30,8 @@ class NET_EXPORT DnsClient {
   // Returns NULL if the current config is not valid.
   virtual DnsTransactionFactory* GetTransactionFactory() = 0;
 
+  virtual AddressSorter* GetAddressSorter() = 0;

[cbentzel, 2012/07/30 15:53:43]

Should this clarify how long the returned pointer is valid for? 

[szym, 2012/07/30 16:28:45]

As long as GetTransactionFactory. I'll add explicit comments.

+
   // Creates default client.
   static scoped_ptr<DnsClient> CreateClient(NetLog* net_log);
 };