[net] HostResolverImpl + DnsTransaction + DnsConfigService = Asynchronous DNS ready for experiments.

net/dns/dns_response.h

Index: net/dns/dns_response.h
diff --git a/net/dns/dns_response.h b/net/dns/dns_response.h
index 764517a37047354dd2fd9fbd8e6c57e4b0e41294..09ffdf43d7d4a4621ea547f667e4076606c8b82b 100644
--- a/net/dns/dns_response.h
+++ b/net/dns/dns_response.h
@@ -11,11 +11,13 @@
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/string_piece.h"
+#include "base/time.h"
 #include "net/base/net_export.h"
 #include "net/base/net_util.h"
 
 namespace net {
 
+class AddressList;
 class DnsQuery;
 class IOBufferWithSize;
 
@@ -130,6 +132,11 @@ class NET_EXPORT_PRIVATE DnsResponse {
   DISALLOW_COPY_AND_ASSIGN(DnsResponse);
 };
 
+// Extracts an AddressList from a DnsResponse. Returns true if succeeded.
+bool DnsResponseToAddressList(const DnsResponse* response,
+                              AddressList* addr_list,
+                              base::TimeDelta* ttl);
+
 }  // namespace net
 
 #endif  // NET_DNS_DNS_RESPONSE_H_