tools: Fix extensions path in check_grd_for_unused_strings.py

tools/check_grd_for_unused_strings.py

 #!/usr/bin/env python
 # 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.
 
 """Without any args, this simply loads the IDs out of a bunch of the Chrome GRD
 files, and then checks the subset of the code that loads the strings to try
 and figure out what isn't in use any more.
 You can give paths to GRD files and source directories to control what is
 check instead.
@@ skipping 134 matching lines @@
       os.path.join(chrome_app_res_dir, 'locale_settings_google_chromeos.grd'),
       os.path.join(chrome_app_res_dir, 'locale_settings_linux.grd'),
       os.path.join(chrome_app_res_dir, 'locale_settings_mac.grd'),
       os.path.join(chrome_app_res_dir, 'locale_settings_win.grd'),
       os.path.join(chrome_app_dir, 'theme', 'theme_resources.grd'),
       os.path.join(chrome_dir, 'browser', 'browser_resources.grd'),
       os.path.join(chrome_dir, 'common', 'common_resources.grd'),
       os.path.join(chrome_dir, 'renderer', 'resources',
                    'renderer_resources.grd'),
       os.path.join(device_base_dir, 'bluetooth', 'bluetooth_strings.grd'),
-      os.path.join(src_dir, 'extensions', 'extensions_strings.grd'),
+      os.path.join(src_dir, 'extensions', 'strings', 'extensions_strings.grd'),
       os.path.join(src_dir, 'ui', 'resources', 'ui_resources.grd'),
       os.path.join(src_dir, 'ui', 'webui', 'resources', 'webui_resources.grd'),
       os.path.join(ui_strings_dir, 'app_locale_settings.grd'),
       os.path.join(ui_strings_dir, 'ui_strings.grd'),
       os.path.join(ui_chromeos_dir, 'ui_chromeos_strings.grd'),
     ]
 
   # If no source directories were given, default them:
   if len(src_dirs) == 0:
     src_dirs = [
       os.path.join(src_dir, 'app'),
       os.path.join(src_dir, 'ash'),
       os.path.join(src_dir, 'chrome'),
       os.path.join(src_dir, 'components'),
       os.path.join(src_dir, 'content'),
       os.path.join(src_dir, 'device'),
       os.path.join(src_dir, 'extensions'),
       os.path.join(src_dir, 'ui'),
       # nsNSSCertHelper.cpp has a bunch of ids
       os.path.join(src_dir, 'third_party', 'mozilla_security_manager'),
       os.path.join(chrome_dir, 'installer'),
     ]
 
   return CheckForUnusedGrdIDsInSources(grd_files, src_dirs)
 
 
 if __name__ == '__main__':
   sys.exit(main())