Remove #pragma once. Just from base/ for now.

base/mach_ipc_mac.h

 // 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 BASE_MACH_IPC_MAC_H_
 #define BASE_MACH_IPC_MAC_H_
-#pragma once
 
 #include <mach/mach.h>
 #include <mach/message.h>
 #include <servers/bootstrap.h>
 #include <sys/types.h>
 
 #include <CoreServices/CoreServices.h>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
@@ skipping 300 matching lines @@
 // Note that unless the calling task has send rights to the passed task port,
 // this will fail unless the calling task is running as root.
 kern_return_t BASE_EXPORT GetNumberOfMachPorts(mach_port_t task_port,
                                                int* port_count);
 
 }  // namespace mac
 
 }  // namespace base
 
 #endif // BASE_MACH_IPC_MAC_H_