Access BackendUsage through ClosedWorld

pkg/compiler/lib/src/js_emitter/full_emitter/interceptor_emitter.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.
 
 library dart2js.js_emitter.full_emitter.interceptor_emitter;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 import '../../elements/entities.dart';
 import '../../js/js.dart' as jsAst;
 import '../../js/js.dart' show js;
@@ skipping 88 matching lines @@
    * If [JSInvocationMirror._invokeOn] has been compiled, emit all the
    * possible selector names that are intercepted into the
    * [interceptedNames] embedded global. The implementation of
    * [_invokeOn] will use it to determine whether it should call the
    * method with an extra parameter.
    */
   jsAst.ObjectInitializer generateInterceptedNamesSet() {
     // We could also generate the list of intercepted names at
     // runtime, by running through the subclasses of Interceptor
     // (which can easily be identified).
-    if (!backend.backendUsage.isInvokeOnUsed) return null;
+    if (!closedWorld.backendUsage.isInvokeOnUsed) return null;
 
     Iterable<jsAst.Name> invocationNames = interceptorInvocationNames.toList()
       ..sort();
     ;
     List<jsAst.Property> properties = invocationNames.map((jsAst.Name name) {
       return new jsAst.Property(js.quoteName(name), js.number(1));
     }).toList();
     return new jsAst.ObjectInitializer(properties, isOneLiner: true);
   }
 
   /**
    * Emit initializer for `typeToInterceptorMap` data structure used by
    * `findInterceptorForType`.  See declaration of `typeToInterceptor` in
    * `interceptors.dart`.
    */
   jsAst.Statement buildTypeToInterceptorMap(Program program) {
     jsAst.Expression array = program.typeToInterceptorMap;
     if (array == null) return js.comment("Empty type-to-interceptor map.");
 
     jsAst.Expression typeToInterceptorMap = emitter
         .generateEmbeddedGlobalAccess(embeddedNames.TYPE_TO_INTERCEPTOR_MAP);
     return js.statement('# = #', [typeToInterceptorMap, array]);
   }
 }