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

net/dns/dns_test_util.cc

Index: net/dns/dns_test_util.cc
diff --git a/net/dns/dns_test_util.cc b/net/dns/dns_test_util.cc
index 051f595e5a87df15c5b3806970690b9f06f03bdf..bae5fb1b701d252a659f013034e1fead8c08eb36 100644
--- a/net/dns/dns_test_util.cc
+++ b/net/dns/dns_test_util.cc
@@ -14,6 +14,7 @@
 #include "net/base/dns_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
+#include "net/dns/address_sorter.h"
 #include "net/dns/dns_client.h"
 #include "net/dns/dns_config_service.h"
 #include "net/dns/dns_protocol.h"
@@ -133,6 +134,15 @@ class MockTransactionFactory : public DnsTransactionFactory {
   }
 };
 
+class MockAddressSorter : public AddressSorter {
+ public:
+  virtual ~MockAddressSorter() {}
+  virtual bool Sort(AddressList* list) const OVERRIDE {
+    // Do nothing.
+    return true;
+  }
+};
+
 // MockDnsClient provides MockTransactionFactory.
 class MockDnsClient : public DnsClient {
  public:
@@ -151,9 +161,14 @@ class MockDnsClient : public DnsClient {
     return config_.IsValid() ? &factory_ : NULL;
   }
 
+  virtual AddressSorter* GetAddressSorter() OVERRIDE {
+    return &address_sorter_;
+  }
+
  private:
   DnsConfig config_;
   MockTransactionFactory factory_;
+  MockAddressSorter address_sorter_;
 };
 
 }  // namespace