Use entities in class_stub_generator.

pkg/compiler/lib/src/js_backend/backend.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.
 
 library js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 834 matching lines @@
 
   bool isNativeOrExtendsNative(ClassElement element) {
     if (element == null) return false;
     if (isNative(element) || isJsInterop(element)) {
       return true;
     }
     assert(element.isResolved);
     return isNativeOrExtendsNative(element.superclass);
   }
 
-  bool isInterceptedMethod(Element element) {
+  bool isInterceptedMethod(MemberElement element) {
     if (!element.isInstanceMember) return false;
     if (element.isGenerativeConstructorBody) {
       return isNativeOrExtendsNative(element.enclosingClass);
     }
     return interceptedElements[element.name] != null;
   }
 
   bool fieldHasInterceptedGetter(Element element) {
     assert(element.isField);
     return interceptedElements[element.name] != null;
@@ skipping 2420 matching lines @@
   @override
   bool isNativeClass(ClassElement element) {
     return helpers.backend.isNative(element);
   }
 
   @override
   bool isNativeMember(MemberElement element) {
     return helpers.backend.isNative(element);
   }
 }