implement things needed to run net/disk_cache/backend_unittest

base/file_util.h

 // Copyright (c) 2006-2008 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_
 
@@ skipping 114 matching lines @@
 //
 // WARNING: USING THIS WITH recursive==true IS EQUIVALENT
 //          TO "rm -rf", SO USE WITH CAUTION.
 bool Delete(const std::wstring& path, bool recursive);
 
 // Moves the given path, whether it's a file or a directory.
 // Returns true if successful, false otherwise.
 bool Move(const std::wstring& from_path, const std::wstring& to_path);
 
 // Copies a single file. Use CopyDirectory to copy directories.
+//
+// Behavior regarding attributes, permissions, metadata, etc is not guaranteed,
+// which means it may differ across platforms.
 bool CopyFile(const std::wstring& from_path, const std::wstring& to_path);
 
 // Copies the given path, and optionally all subdirectories and their contents
 // as well.
 // If there are files existing under to_path, always overwrite.
 // Returns true if successful, false otherwise.
 // Dont't use wildcards on the names, it may stop working without notice.
 //
 // If you only need to copy a file use CopyFile, it's faster.
+//
+// Behavior regarding attributes, permissions, metadata, etc is not guaranteed,
+// which means it may differ across platforms.
 bool CopyDirectory(const std::wstring& from_path, const std::wstring& to_path,
                    bool recursive);
 
 // Returns true if the given path exists on the local filesystem,
 // false otherwise.
 bool PathExists(const std::wstring& path);
 
 // Returns true if the given path is writable by the user, false otherwise.
 bool PathIsWritable(const std::wstring& path);
 
@@ skipping 163 matching lines @@
 
 // Renames a file using the MoveFileEx API and ensures that the target file gets
 // the correct security descriptor in the new path.
 bool RenameFileAndResetSecurityDescriptor(
     const std::wstring& source_file_path,
     const std::wstring& target_file_path);
 
 }  // namespace file_util
 
 #endif  // BASE_FILE_UTIL_H_