Patch refactoring.

lib/compiler/implementation/js_backend/constant_emitter.dart

 // 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.
 
 class ConstantEmitter implements ConstantVisitor {
   final Compiler compiler;
   final Namer namer;
 
   CodeBuffer buffer;
   bool shouldEmitCanonicalVersion;
@@ skipping 188 matching lines @@
 
       shouldEmitCanonicalVersion = true;
 
       ClassElement classElement = constant.type.element;
       buffer.add("new ");
       buffer.add(getJsConstructor(classElement));
       buffer.add("(");
       // The arguments of the JavaScript constructor for any given Dart class
       // are in the same order as the members of the class element.
       int emittedArgumentCount = 0;
-      classElement.forEachInstanceField(
+      classElement.implementation.forEachInstanceField(
           includeBackendMembers: true,
           includeSuperMembers: true,
           f: (ClassElement enclosing, Element field) {
             if (emittedArgumentCount != 0) buffer.add(", ");
             if (field.name == MapConstant.LENGTH_NAME) {
               buffer.add(constant.keys.entries.length);
             } else if (field.name == MapConstant.JS_OBJECT_NAME) {
               writeJsMap();
             } else if (field.name == MapConstant.KEYS_NAME) {
               emitCanonicalVersionOfConstant(constant.keys, buffer);
@@ skipping 23 matching lines @@
       buffer.add(getJsConstructor(constant.type.element));
       buffer.add("(");
       for (int i = 0; i < constant.fields.length; i++) {
         if (i != 0) buffer.add(", ");
         _visit(constant.fields[i]);
       }
       buffer.add(")");
     }
   }
 }