Revert setuid sandbox as a "init process" changes

sandbox/linux/suid/init_process.h

Index: sandbox/linux/suid/init_process.h
diff --git a/sandbox/linux/suid/init_process.h b/sandbox/linux/suid/init_process.h
deleted file mode 100644
index 45bc69a227ca8f2f1fba6d5b28fa69f3863a5af8..0000000000000000000000000000000000000000
--- a/sandbox/linux/suid/init_process.h
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2012 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_LINUX_SUID_INIT_PROCESS_H_
-#define SANDBOX_LINUX_SUID_INIT_PROCESS_H_
-
-void SystemInitProcess(int init_fd, int child_pid, int proc_fd, int null_fd)
-  __attribute__((noreturn));
-
-#endif  // SANDBOX_LINUX_SUID_INIT_PROCESS_H_