Revert of Switch to standard integer types in sandbox/.

sandbox/linux/seccomp-bpf-helpers/baseline_policy_unittest.cc

 // Copyright 2014 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 "sandbox/linux/seccomp-bpf-helpers/baseline_policy.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <netinet/in.h>
 #include <sched.h>
 #include <signal.h>
-#include <stddef.h>
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <time.h>
@@ skipping 353 matching lines @@
   int fds[2];
   PCHECK(socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0);
   int id;
   setsockopt(fds[0], SOL_SOCKET, SO_DEBUG, &id, sizeof(id));
 }
 #endif
 
 }  // namespace
 
 }  // namespace sandbox