Use entities in class_stub_generator.

pkg/compiler/lib/src/js_emitter/native_generator.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.js_emitter.native_generator;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show js;
-import '../js_backend/js_backend.dart'
-    show
-    JavaScriptBackend;
+import '../js_backend/js_backend.dart' show JavaScriptBackend;
 
 import 'model.dart';
 
 class NativeGenerator {
   static bool needsIsolateAffinityTagInitialization(JavaScriptBackend backend) {
     return backend.needToInitializeIsolateAffinityTag;
   }
 
   /// Generates the code for isolate affinity tags.
   ///
@@ skipping 187 matching lines @@
           'info': infoAccess,
           'constructor': constructorAccess,
           'subclassRead': subclassRead,
           'interceptorsByTagAccess': interceptorsByTagAccess,
           'leafTagsAccess': leafTagsAccess,
           'nativeSuperclassTagName': embeddedNames.NATIVE_SUPERCLASS_TAG_NAME,
           'allowNativesSubclassing': true
         });
   }
 }