Move file_util to base/files/ directory.

base/files/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.
 
 // This file contains utility functions for dealing with the local
 // filesystem.
 
-#ifndef BASE_FILE_UTIL_H_
-#define BASE_FILE_UTIL_H_
+#ifndef BASE_FILES_FILE_UTIL_H_
+#define BASE_FILES_FILE_UTIL_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_POSIX)
 #include <sys/stat.h>
 #include <unistd.h>
 #endif
 
@@ skipping 409 matching lines @@
 // Returns true if all operations succeed.
 // This function simulates Move(), but unlike Move() it works across volumes.
 // This function is not transactional.
 BASE_EXPORT bool CopyAndDeleteDirectory(const FilePath& from_path,
                                         const FilePath& to_path);
 #endif  // defined(OS_WIN)
 
 }  // namespace internal
 }  // namespace base
 
-#endif  // BASE_FILE_UTIL_H_
+#endif  // BASE_FILES_FILE_UTIL_H_