Access BackendUsage through ClosedWorld

pkg/compiler/lib/src/universe/resolution_world_builder.dart

 // Copyright (c) 2017, 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.
 
 part of world_builder;
 
 abstract class ResolutionWorldBuilder implements WorldBuilder, OpenWorld {
   /// Set of all local functions in the program. Used by the mirror tracking
   /// system to find all live closure instances.
   Iterable<Local> get localFunctions;
@@ skipping 317 matching lines @@
   final Set<FunctionEntity> closurizedMembersWithFreeTypeVariables =
       new Set<FunctionEntity>();
 
   final ElementEnvironment _elementEnvironment;
 
   final CommonElements _commonElements;
 
   final NativeBasicData _nativeBasicData;
   final NativeDataBuilder _nativeDataBuilder;
   final InterceptorDataBuilder _interceptorDataBuilder;
+  final BackendUsageBuilder _backendUsageBuilder;
 
   final SelectorConstraintsStrategy selectorConstraintsStrategy;
 
   bool hasRuntimeTypeSupport = false;
   bool hasIsolateSupport = false;
   bool hasFunctionApplySupport = false;
 
   bool _closed = false;
   ClosedWorld _closedWorldCache;
   FunctionSetBuilder _allFunctions;
@@ skipping 12 matching lines @@
   final Set<ConstantValue> _constantValues = new Set<ConstantValue>();
 
   bool get isClosed => _closed;
 
   ResolutionWorldBuilderBase(
       this._elementEnvironment,
       this._commonElements,
       this._nativeBasicData,
       this._nativeDataBuilder,
       this._interceptorDataBuilder,
+      this._backendUsageBuilder,
       this.selectorConstraintsStrategy) {
     _allFunctions = new FunctionSetBuilder();
   }
 
   Iterable<ClassEntity> get processedClasses => _processedClasses.keys
       .where((cls) => _processedClasses[cls].isInstantiated);
 
   ClosedWorld get closedWorldForTesting {
     if (!_closed) {
       throw new SpannableAssertionFailure(
@@ skipping 537 matching lines @@
 }
 
 abstract class KernelResolutionWorldBuilderBase
     extends ResolutionWorldBuilderBase {
   KernelResolutionWorldBuilderBase(
       ElementEnvironment elementEnvironment,
       CommonElements commonElements,
       NativeBasicData nativeBasicData,
       NativeDataBuilder nativeDataBuilder,
       InterceptorDataBuilder interceptorDataBuilder,
+      BackendUsageBuilder backendUsageBuilder,
       SelectorConstraintsStrategy selectorConstraintsStrategy)
       : super(
             elementEnvironment,
             commonElements,
             nativeBasicData,
             nativeDataBuilder,
             interceptorDataBuilder,
+            backendUsageBuilder,
             selectorConstraintsStrategy);
 
   @override
   ClosedWorld closeWorld() {
     Map<ClassEntity, Set<ClassEntity>> typesImplementedBySubclasses =
         populateHierarchyNodes();
     _closed = true;
     return _closedWorldCache = new KernelClosedWorld(
         commonElements: _commonElements,
         nativeData: _nativeDataBuilder.close(),
         interceptorData: _interceptorDataBuilder.close(),
+        backendUsage: _backendUsageBuilder.close(),
         // TODO(johnniwinther): Compute these.
         constantSystem: null,
-        backendUsage: null,
         resolutionWorldBuilder: this,
         functionSet: _allFunctions.close(),
         allTypedefs: _allTypedefs,
         mixinUses: _mixinUses,
         typesImplementedBySubclasses: typesImplementedBySubclasses,
         classHierarchyNodes: _classHierarchyNodes,
         classSets: _classSets);
   }
 
   @override
   void registerClass(ClassEntity cls) {
     throw new UnimplementedError('KernelResolutionWorldBuilder.registerClass');
   }
 }