Replace calls to rand_s with calls to RtlGenRandom

sandbox/win/src/sandbox_rand.h

Index: sandbox/win/src/sandbox_rand.h
diff --git a/sandbox/win/src/sandbox_rand.h b/sandbox/win/src/sandbox_rand.h
new file mode 100644
index 0000000000000000000000000000000000000000..7f482870f88cd0b8abbfb714a0632b45e4f618e8
--- /dev/null
+++ b/sandbox/win/src/sandbox_rand.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2015 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 SANDBOX_SRC_SANDBOX_RAND_H_
+#define SANDBOX_SRC_SANDBOX_RAND_H_
+
+#include "base/basictypes.h"
+
+namespace sandbox {
+
+// Generate a random value in |random_value|. Returns true on success.
+bool GetRandom(unsigned int* random_value);
+
+}  // namespace sandbox
+
+#endif  // SANDBOX_SRC_SANDBOX_RAND_H_