Register created closure class with the world.

pkg/compiler/lib/src/js_model/js_strategy.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.
 
 library dart2js.js_model.strategy;
 
 import '../closure.dart' show ClosureConversionTask;
 import '../common.dart';
 import '../common/tasks.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
 import '../constants/constant_system.dart';
-import '../elements/elements.dart' show ClassElement, TypedefElement;
+import '../elements/elements.dart' show TypedefElement;
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../enqueue.dart';
 import '../io/source_information.dart';
 import '../js_emitter/sorter.dart';
 import '../js/js_source_mapping.dart';
 import '../js_backend/backend.dart';
 import '../js_backend/backend_usage.dart';
 import '../js_backend/constant_system_javascript.dart';
 import '../js_backend/interceptor_data.dart';
@@ skipping 353 matching lines @@
             liveNativeClasses,
             liveInstanceMembers,
             assignedInstanceMembers,
             allTypedefs,
             mixinUses,
             typesImplementedBySubclasses,
             classHierarchyNodes,
             classSets);
 
   @override
-  void registerClosureClass(ClassElement cls) {
-    throw new UnimplementedError('JsClosedWorld.registerClosureClass');
+  void registerClosureClass(ClassEntity cls, bool fromInstanceMember) {
+    // Tell the hierarchy that this is the super class. then we can use
+    // .getSupertypes(class)
+    ClassEntity superclass = fromInstanceMember
+        ? commonElements.boundClosureClass
+        : commonElements.closureClass;
+    ClassHierarchyNode parentNode = getClassHierarchyNode(superclass);
+    ClassHierarchyNode node = new ClassHierarchyNode(
+        parentNode, cls, getHierarchyDepth(superclass) + 1);
+    addClassHierarchyNode(cls, node);
+    for (InterfaceType type in getOrderedTypeSet(superclass).types) {
+      // TODO(efortuna): assert that the FunctionClass is in this ordered set.
+      // If not, we need to explicitly add node as a subtype of FunctionClass.
+      ClassSet subtypeSet = getClassSet(type.element);
+      subtypeSet.addSubtype(node);
+    }
+    addClassSet(cls, new ClassSet(node));
+    elementMap.addClosureClass(cls, new InterfaceType(superclass, const []));
+    node.isDirectlyInstantiated = true;
   }
 }