Revert "Element.style is not null"

tools/dom/scripts/dartmetadata.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality to provide Dart metadata for
 DOM APIs.
 """
 
 import copy
@@ skipping 90 matching lines @@
     'Element.getElementsByTagName': [
       "@Creates('NodeList|HtmlCollection')",
       "@Returns('NodeList|HtmlCollection')",
     ],
 
     'Element.getElementsByClassName': [
       "@Creates('NodeList|HtmlCollection')",
       "@Returns('NodeList|HtmlCollection')",
     ],
 
-    'Element.style': [  # Element.style is never null.
-      "@Returns('CssStyleDeclaration')",
-    ],
-
     "ErrorEvent.error": [
       "@Creates('Null')", # Only returns values created elsewhere.
     ],
 
     # To be in callback with the browser-created Event, we had to have called
     # addEventListener on the target, so we avoid
     'Event.currentTarget': [
       "@Creates('Null')",
       "@Returns('EventTarget|=Object')",
     ],
@@ skipping 713 matching lines @@
       pass
     else:
       _logger.warn('Unknown support_level - %s:%s' % (interface_id, member_id))
 
     return annotations
 
   def Flush(self):
     json_file = open(self._api_status_path, 'w+')
     json.dump(self._types, json_file, indent=2, separators=(',', ': '), sort_keys=True)
     json_file.close()