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

base/test/test_file_util.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_TEST_TEST_FILE_UTIL_H_
 #define BASE_TEST_TEST_FILE_UTIL_H_
-#pragma once
 
 // File utility functions used only by tests.
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 
 class FilePath;
 
@@ skipping 49 matching lines @@
   const FilePath path_;
   void* info_;  // The opaque stored permission information.
   size_t length_;  // The length of the stored permission information.
 
   DISALLOW_COPY_AND_ASSIGN(PermissionRestorer);
 };
 
 }  // namespace file_util
 
 #endif  // BASE_TEST_TEST_FILE_UTIL_H_