Add ElementKind for factory constructors.

pkg/compiler/lib/src/parser/partial_elements.dart

 // Copyright (c) 2015, 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.
 
 library dart2js.parser.partial_elements;
 
 import '../common.dart';
 import '../common/resolution.dart' show
     Parsing,
     Resolution;
@@ skipping 219 matching lines @@
     reusePartialFunctionMixin();
   }
 
   PartialSetterElement copyWithEnclosing(Element enclosing) {
     return new PartialSetterElement(
         name, beginToken, getOrSet, endToken, modifiers, enclosing,
         hasBody: hasBody);
   }
 }
 
+// TODO(johnniwinther): Create [PartialGenerativeConstructor] and
+// [PartialFactoryConstructor] subclasses and make this abstract.
 class PartialConstructorElement extends ConstructorElementX
     with PartialElement, PartialFunctionMixin {
   PartialConstructorElement(String name,
                             Token beginToken,
                             Token endToken,
                             ElementKind kind,
                             Modifiers modifiers,
                             Element enclosing)
       : super(name, kind, modifiers, enclosing) {
     init(beginToken, null, endToken);
@@ skipping 239 matching lines @@
       } on ParserError catch (e) {
         partial.hasParseError = true;
         return new ErrorNode(element.position, e.reason);
       }
       Node node = listener.popNode();
       assert(listener.nodes.isEmpty);
       return node;
     });
   });
 }