Use entities in ClosedWorld interface

pkg/compiler/lib/src/enqueue.dart

Index: pkg/compiler/lib/src/enqueue.dart
diff --git a/pkg/compiler/lib/src/enqueue.dart b/pkg/compiler/lib/src/enqueue.dart
index 62734f16d46c2a159aee79f4437a5f3dad74a462..9e9d9365a3e1b3cd815d2a8f186075516d11a2ec 100644
--- a/pkg/compiler/lib/src/enqueue.dart
+++ b/pkg/compiler/lib/src/enqueue.dart
@@ -14,7 +14,6 @@ import 'common/work.dart' show WorkItem;
 import 'common.dart';
 import 'compiler.dart' show Compiler, GlobalDependencyRegistry;
 import 'options.dart';
-import 'elements/resolution_types.dart' show DartType, InterfaceType;
 import 'elements/elements.dart'
     show
         AnalyzableElement,
@@ -24,8 +23,8 @@ import 'elements/elements.dart'
         Entity,
         MemberElement;
 import 'elements/entities.dart';
+import 'elements/resolution_types.dart' show DartType, InterfaceType;
 import 'native/native.dart' as native;
-import 'types/types.dart' show TypeMaskStrategy;
 import 'universe/world_builder.dart';
 import 'universe/use.dart'
     show DynamicUse, StaticUse, StaticUseKind, TypeUse, TypeUseKind;