Access BackendUsage through ClosedWorld

pkg/compiler/lib/src/js_emitter/code_emitter_task.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 dart2js.js_emitter.code_emitter_task;
 
 import 'package:js_runtime/shared/embedded_names.dart' show JsBuiltin;
 
 import '../common.dart';
 import '../common/tasks.dart' show CompilerTask;
@@ skipping 179 matching lines @@
       ProgramBuilder programBuilder = new ProgramBuilder(
           compiler.options,
           compiler.reporter,
           compiler.elementEnvironment,
           compiler.commonElements,
           compiler.types,
           compiler.deferredLoadTask,
           compiler.closureToClassMapper,
           compiler.codegenWorldBuilder,
           backend.nativeCodegenEnqueuer,
-          backend.backendUsage,
+          closedWorld.backendUsage,
           backend.constants,
           closedWorld.nativeData,
           backend.rtiNeed,
           backend.mirrorsData,
           closedWorld.interceptorData,
           backend.superMemberData,
           typeTestRegistry.rtiChecks,
           backend.rtiEncoder,
           backend.rtiSubstitutions,
           backend.jsInteropAnalysis,
@@ skipping 67 matching lines @@
 
   /// Returns the JS code for accessing the given [constant].
   jsAst.Expression constantReference(ConstantValue constant);
 
   /// Returns the JS template for the given [builtin].
   jsAst.Template templateForBuiltin(JsBuiltin builtin);
 
   /// Returns the size of the code generated for a given output [unit].
   int generatedSize(OutputUnit unit);
 }