clang/win: Let some chromium_code targets build with -Wextra.

chrome/browser/policy/policy_path_parser_win.cc

 // Copyright (c) 2011 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 <shlobj.h>
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
 
 #include "chrome/browser/policy/policy_path_parser.h"
 
@@ skipping 59 matching lines @@
   if (result.length() == 0)
     return result;
   // Sanitize quotes in case of any around the whole string.
   if (result.length() > 1 &&
       ((result[0] == L'"' && result[result.length() - 1] == L'"') ||
        (result[0] == L'\'' && result[result.length() - 1] == L'\''))) {
     // Strip first and last char which should be matching quotes now.
     result = result.substr(1, result.length() - 2);
   }
   // First translate all path variables we recognize.
-  for (int i = 0; i < arraysize(win_folder_mapping); ++i) {
+  for (size_t i = 0; i < arraysize(win_folder_mapping); ++i) {
     size_t position = result.find(win_folder_mapping[i].name);
     if (position != std::wstring::npos) {
       WCHAR path[MAX_PATH];
       ::SHGetSpecialFolderPath(0, path, win_folder_mapping[i].id, false);
       std::wstring path_string(path);
       result.replace(position, wcslen(win_folder_mapping[i].name), path_string);
     }
   }
   // Next translate other windows specific variables.
   size_t position = result.find(kUserNamePolicyVarName);
@@ skipping 54 matching lines @@
 void CheckUserDataDirPolicy(base::FilePath* user_data_dir) {
   DCHECK(user_data_dir);
   // Policy from the HKLM hive has precedence over HKCU.
   if (!LoadUserDataDirPolicyFromRegistry(HKEY_LOCAL_MACHINE, user_data_dir))
     LoadUserDataDirPolicyFromRegistry(HKEY_CURRENT_USER, user_data_dir);
 }
 
 }  // namespace path_parser
 
 }  // namespace policy