DnsQuery: changed raw function pointer to callback.

net/base/rand_callback.h

Index: net/base/rand_callback.h
diff --git a/net/base/rand_callback.h b/net/base/rand_callback.h
new file mode 100644
index 0000000000000000000000000000000000000000..894b0206827e1421f0a72f729f9b5a383db86038
--- /dev/null
+++ b/net/base/rand_callback.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_BASE_RAND_CALLBACK_H_
+#define NET_BASE_RAND_CALLBACK_H_
+#pragma once
+
+#include "base/callback.h"
+
+namespace net {
+
+typedef base::Callback<int(int, int)> RandIntCallback;
+
+}  // namespace net
+
+#endif  // NET_BASE_RAND_CALLBACK_H_