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

base/process_util_unittest_mac.h

 // Copyright (c) 2010 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.
 
 // This file contains helpers for the process_util_unittest to allow it to fully
 // test the Mac code.
 
 #ifndef BASE_PROCESS_UTIL_UNITTEST_MAC_H_
 #define BASE_PROCESS_UTIL_UNITTEST_MAC_H_
-#pragma once
 
 #include "base/basictypes.h"
 
 namespace base {
 
 // Allocates memory via system allocators. Alas, they take a _signed_ size for
 // allocation.
 void* AllocateViaCFAllocatorSystemDefault(ssize_t size);
 void* AllocateViaCFAllocatorMalloc(ssize_t size);
 void* AllocateViaCFAllocatorMallocZone(ssize_t size);
 
 #if !defined(ARCH_CPU_64_BITS)
 // See process_util_unittest_mac.mm for an explanation of why this function
 // isn't implemented for the 64-bit environment.
 
 // Allocates a huge Objective C object.
 void* AllocatePsychoticallyBigObjCObject();
 
 #endif  // !ARCH_CPU_64_BITS
 
 }  // namespace base
 
 #endif  // BASE_PROCESS_UTIL_UNITTEST_MAC_H_