Implement some missing file util functions.

base/file_util.cc

 // 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.
 
 #include "base/file_util.h"
 
 #include <stdio.h>
 
 #include <fstream>
 
@@ skipping 352 matching lines @@
 bool GetFileSize(const std::wstring& file_path, int64* file_size) {
   return GetFileSize(FilePath::FromWStringHack(file_path), file_size);
 }
 bool GetTempDir(std::wstring* path_str) {
   FilePath path;
   if (!GetTempDir(&path))
     return false;
   *path_str = path.ToWStringHack();
   return true;
 }
+FILE* OpenFile(const std::wstring& filename, const char* mode) {
+  return OpenFile(FilePath::FromWStringHack(filename), mode);
+}
+bool SetCurrentDirectory(const std::wstring& directory) {
+  return SetCurrentDirectory(FilePath::FromWStringHack(directory));
+}
 
 }  // namespace