Support top-level field declaration and assignment in analyzer2dart.

pkg/analyzer2dart/lib/src/modely.dart

 // Copyright (c) 2014, 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.
 
 part of analyzer2dart.element_converter;
 
 
 /// Base [dart2js.Element] implementation for converted analyzer elements.
 class ElementY extends dart2js.Element {
   final ElementConverter converter;
@@ skipping 682 matching lines @@
          VariableElementMixin
     implements dart2js.FieldElement {
 
   analyzer.TopLevelVariableElement get element => super.element;
 
   dart2js.ElementKind get kind => dart2js.ElementKind.FIELD;
 
   @override
   dart2js.DartType get type => converter.convertType(element.type);
 
+  @override
+  bool get isFinal => element.isFinal;
+
+  @override
+  bool get isConst => element.isConst;
+
   TopLevelVariableElementY(ElementConverter converter,
                            analyzer.TopLevelVariableElement element)
       : super(converter, element);
 
   @override
   get nestedClosures => unsupported('nestedClosures');
 }
 
 abstract class LocalElementMixin implements ElementY, dart2js.LocalElement {
 
@@ skipping 68 matching lines @@
 
   @override
   bool get isRedirectingFactory => unsupported('isRedirectingFactory');
 
   @override
   get nestedClosures => unsupported('nestedClosures');
 
   @override
   get type => unsupported('type');
 }