Fix dartium build breakage

tools/dom/scripts/generator.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 for systems to generate
 Dart APIs from the IDL database."""
 
 import copy
 import json
@@ skipping 996 matching lines @@
                               webcore_getter_name='getUnsignedIntegralAttribute',
                               webcore_setter_name='setUnsignedIntegralAttribute'),
     'long long': TypeData(clazz='Primitive', dart_type='int'),
     'unsigned long long': TypeData(clazz='Primitive', dart_type='int'),
     'float': TypeData(clazz='Primitive', dart_type='num', native_type='double'),
     'double': TypeData(clazz='Primitive', dart_type='num'),
 
     'any': TypeData(clazz='Primitive', dart_type='Object', native_type='ScriptValue'),
     'Array': TypeData(clazz='Primitive', dart_type='List'),
     'custom': TypeData(clazz='Primitive', dart_type='dynamic'),
-    'union': TypeData(clazz='Primitive', dart_type='dynamic'),
     'ClientRect': TypeData(clazz='Interface',
         dart_type='Rect', suppress_interface=True),
     'Date': TypeData(clazz='Primitive', dart_type='DateTime', native_type='double'),
     'DOMObject': TypeData(clazz='Primitive', dart_type='Object', native_type='ScriptValue'),
     'DOMString': TypeData(clazz='Primitive', dart_type='String', native_type='String'),
     # TODO(vsm): This won't actually work until we convert the Map to
     # a native JS Map for JS DOM.
     'Dictionary': TypeData(clazz='Primitive', dart_type='Map'),
     'DOMTimeStamp': TypeData(clazz='Primitive', dart_type='int', native_type='unsigned long long'),
     'object': TypeData(clazz='Primitive', dart_type='Object', native_type='ScriptValue'),
@@ skipping 169 matching lines @@
           type_name, type_data, dart_interface_name, self)
 
     if type_data.clazz == 'BasicTypedList':
       dart_interface_name = self._renamer.RenameInterface(
           self._database.GetInterface(type_name))
       return BasicTypedListIDLTypeInfo(
           type_name, type_data, dart_interface_name, self)
 
     class_name = '%sIDLTypeInfo' % type_data.clazz
     return globals()[class_name](type_name, type_data)