Follow up to CL 764533002.

dart/pkg/compiler/lib/src/js_emitter/old_emitter/class_builder.dart

 // Copyright (c) 2013, 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 dart2js.js_emitter;
 
 /**
  * A data structure for collecting fragments of a class definition.
  */
 class ClassBuilder {
@@ skipping 17 matching lines @@
     jsAst.Property property = new jsAst.Property(js.string(name), value);
     properties.add(property);
     return property;
   }
 
   void addField(String field) {
     fields.add(field);
   }
 
   jsAst.ObjectInitializer toObjectInitializer(
-      {bool omitClassDescriptor: false}) {
+      {bool emitClassDescriptor: true}) {
     StringBuffer buffer = new StringBuffer();
     if (superName != null) {
       buffer.write('$superName');
       if (functionType != null) {
         buffer.write(':$functionType');
       }
       buffer.write(';');
     }
     buffer.writeAll(fields, ',');
     var classData = js.string('$buffer');
     if (fieldMetadata != null) {
       // If we need to store fieldMetadata, classData is turned into an array,
       // and the field metadata is appended. So if classData is just a string,
       // there is no field metadata.
       classData =
           new jsAst.ArrayInitializer([classData]..addAll(fieldMetadata));
     }
     List<jsAst.Property> fieldsAndProperties;
-    if (!omitClassDescriptor) {
+    if (emitClassDescriptor) {
       fieldsAndProperties = <jsAst.Property>[];
       fieldsAndProperties.add(
           new jsAst.Property(
               js.string(namer.classDescriptorProperty), classData));
-      fieldsAndProperties
-          ..addAll(properties);
+      fieldsAndProperties.addAll(properties);
     } else {
       fieldsAndProperties = properties;
     }
     return new jsAst.ObjectInitializer(fieldsAndProperties, isOneLiner: false);
   }
 }