Switch to standard integer types in crypto/.

crypto/secure_util.cc

 // 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.
 
+#include <stddef.h>
+
 #include "crypto/secure_util.h"
 
 namespace crypto {
 
 bool SecureMemEqual(const void* s1, const void* s2, size_t n) {
   const unsigned char* s1_ptr = reinterpret_cast<const unsigned char*>(s1);
   const unsigned char* s2_ptr = reinterpret_cast<const unsigned char*>(s2);
   unsigned char tmp = 0;
   for (size_t i = 0; i < n; ++i, ++s1_ptr, ++s2_ptr)
     tmp |= *s1_ptr ^ *s2_ptr;
   return (tmp == 0);
 }
 
 }  // namespace crypto