Use entities in class_stub_generator.

pkg/compiler/lib/src/js_emitter/model.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.
 
 library dart2js.new_js_emitter.model;
 
 import '../constants/values.dart' show ConstantValue;
 import '../deferred_load.dart' show OutputUnit;
-import '../elements/elements.dart' show Element;
+import '../elements/elements.dart' show Element, FieldElement;
 import '../js/js.dart' as js show Expression, Name, Statement, TokenFinalizer;
 import 'js_emitter.dart' show MetadataCollector;
 
 class Program {
   final List<Fragment> fragments;
   final List<Holder> holders;
   final bool outputContainsConstantList;
   final bool needsNativeSupport;
   final bool hasIsolateSupport;
 
@@ skipping 308 matching lines @@
   }
 }
 
 /// A field.
 ///
 /// In general represents an instance field, but for reflection may also
 /// represent static fields.
 class Field {
   /// The element should only be used during the transition to the new model.
   /// Uses indicate missing information in the model.
-  final Element element;
+  final FieldElement element;
 
   final js.Name name;
   final js.Name accessorName;
 
   /// 00: Does not need any getter.
   /// 01:  function() { return this.field; }
   /// 10:  function(receiver) { return receiver.field; }
   /// 11:  function(receiver) { return this.field; }
   final int getterFlags;
 
@@ skipping 180 matching lines @@
             functionType: functionType);
 
   bool get isStatic => true;
 }
 
 class StaticStubMethod extends StubMethod implements StaticMethod {
   Holder holder;
   StaticStubMethod(js.Name name, this.holder, js.Expression code)
       : super(name, code);
 }