Even less reliance on Compiler.closedWorld

pkg/compiler/lib/src/common/backend_api.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.backend_api;
 
 import 'dart:async' show Future;
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenImpact;
@@ skipping 15 matching lines @@
 import '../js_backend/js_backend.dart' as js_backend;
 import '../library_loader.dart' show LibraryLoader, LoadedLibraries;
 import '../native/native.dart' as native show NativeEnqueuer, maybeEnableNative;
 import '../patch_parser.dart'
     show checkNativeAnnotation, checkJsInteropAnnotation;
 import '../serialization/serialization.dart'
     show DeserializerPlugin, SerializerPlugin;
 import '../tree/tree.dart' show Node;
 import '../universe/world_impact.dart'
     show ImpactStrategy, WorldImpact, WorldImpactBuilder;
-import '../world.dart' show ClosedWorldRefiner;
+import '../world.dart' show ClosedWorld, ClosedWorldRefiner;
 import 'codegen.dart' show CodegenWorkItem;
 import 'tasks.dart' show CompilerTask;
 
 abstract class Backend extends Target {
   final Compiler compiler;
 
   Backend(this.compiler);
 
   /// Returns true if the backend supports reflection.
   bool get supportsReflection;
@@ skipping 53 matching lines @@
 
   native.NativeEnqueuer nativeCodegenEnqueuer() {
     return new native.NativeEnqueuer();
   }
 
   /// Generates the output and returns the total size of the generated code.
   int assembleProgram();
 
   List<CompilerTask> get tasks;
 
-  void onResolutionComplete(ClosedWorldRefiner closedWorldRefiner) {}
+  void onResolutionComplete(
+      ClosedWorld closedWorld, ClosedWorldRefiner closedWorldRefiner) {}
   void onTypeInferenceComplete() {}
 
   bool classNeedsRti(ClassElement cls);
   bool methodNeedsRti(FunctionElement function);
 
   /// Enable compilation of code with compile time errors. Returns `true` if
   /// supported by the backend.
   bool enableCodegenWithErrorsIfSupported(Spannable node);
 
   /// Enable deferred loading. Returns `true` if the backend supports deferred
@@ skipping 288 matching lines @@
   ClassElement get boolImplementation;
   ClassElement get nullImplementation;
   ClassElement get uint32Implementation;
   ClassElement get uint31Implementation;
   ClassElement get positiveIntImplementation;
   ClassElement get syncStarIterableImplementation;
   ClassElement get asyncFutureImplementation;
   ClassElement get asyncStarStreamImplementation;
   ClassElement get indexableImplementation;
   ClassElement get mutableIndexableImplementation;
+  ClassElement get indexingBehaviorImplementation;
 
   bool isDefaultEqualityImplementation(Element element);
+  bool isInterceptorClass(ClassElement cls);
+  bool isNative(Element element);
 }