Check equivalence of closed world based on kernel elements.

tests/compiler/dart2js/kernel/closed_world2_test.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.
 
 // Partial test that the closed world computed from [WorldImpact]s derived from
 // kernel is equivalent to the original computed from resolution.
 library dart2js.kernel.closed_world2_test;
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/closure.dart';
@@ skipping 32 matching lines @@
 import '../memory_compiler.dart';
 import '../serialization/helper.dart';
 import '../serialization/model_test_helper.dart';
 import '../serialization/test_helper.dart';
 
 import 'closed_world_test.dart';
 import 'impact_test.dart';
 
 const SOURCE = const {
   'main.dart': '''
-main() {}
+main() {
+  print('Hello World');
+}
 '''
 };
 
 main(List<String> args) {
   Arguments arguments = new Arguments.from(args);
   Uri entryPoint;
   Map<String, String> memorySourceFiles;
   if (arguments.uri != null) {
     entryPoint = arguments.uri;
     memorySourceFiles = const <String, String>{};
   } else {
     entryPoint = Uri.parse('memory:main.dart');
     memorySourceFiles = SOURCE;
   }
 
   asyncTest(() async {
     enableDebugMode();
 
     print('---- analyze-only ------------------------------------------------');
     Compiler compiler1 = compilerFor(
         entryPoint: entryPoint,
         memorySourceFiles: memorySourceFiles,
         options: [Flags.analyzeOnly, Flags.enableAssertMessage]);
     ElementResolutionWorldBuilder.useInstantiationMap = true;
     compiler1.resolution.retainCachesForTesting = true;
     await compiler1.run(entryPoint);
     ResolutionEnqueuer enqueuer1 = compiler1.enqueuer.resolution;
     BackendUsage backendUsage1 = compiler1.backend.backendUsage;
-    compiler1.resolutionWorldBuilder.closeWorld();
+    ClosedWorld closedWorld1 = compiler1.resolutionWorldBuilder.closeWorld();
 
     print('---- analyze-all -------------------------------------------------');
     Compiler compiler = compilerFor(
         entryPoint: entryPoint,
         memorySourceFiles: memorySourceFiles,
         options: [
           Flags.analyzeAll,
           Flags.useKernel,
           Flags.enableAssertMessage
         ]);
@@ skipping 16 matching lines @@
     ResolutionEnqueuerListener resolutionEnqueuerListener = list[0];
     BackendUsageBuilder backendUsageBuilder2 = list[1];
     ImpactTransformer impactTransformer = list[2];
     ResolutionEnqueuer enqueuer2 = new ResolutionEnqueuer(
         compiler.enqueuer,
         compiler.options,
         compiler.reporter,
         const TreeShakingEnqueuerStrategy(),
         resolutionEnqueuerListener,
         new KernelResolutionWorldBuilder(
-            worldBuilder.elementEnvironment,
-            worldBuilder.commonElements,
-            nativeBasicData,
-            const OpenWorldStrategy()),
+            worldBuilder, nativeBasicData, const OpenWorldStrategy()),
         new KernelWorkItemBuilder(worldBuilder, impactTransformer),
         'enqueuer from kelements');
-    computeClosedWorld(
+    ClosedWorld closedWorld2 = computeClosedWorld(
         compiler.reporter, enqueuer2, worldBuilder.elementEnvironment);
     BackendUsage backendUsage2 = backendUsageBuilder2.close();
     checkBackendUsage(backendUsage1, backendUsage2, equivalence);
 
     checkResolutionEnqueuers(backendUsage1, backendUsage2, enqueuer1, enqueuer2,
         elementEquivalence: equivalence.entityEquivalence,
         typeEquivalence: (ResolutionDartType a, DartType b) {
       return equivalence.typeEquivalence(unalias(a), b);
     }, elementFilter: elementFilter, verbose: arguments.verbose);
+
+    checkClosedWorlds(closedWorld1, closedWorld2, equivalence.entityEquivalence,
+        verbose: arguments.verbose);
   });
 }
 
 List createKernelResolutionEnqueuerListener(
     CompilerOptions options,
     DiagnosticReporter reporter,
     DeferredLoadTask deferredLoadTask,
     KernelWorldBuilder worldBuilder,
     NativeBasicData nativeBasicData) {
   ElementEnvironment elementEnvironment = worldBuilder.elementEnvironment;
@@ skipping 219 matching lines @@
       usage2.isInvokeOnUsed);
   check(usage1, usage2, 'isRuntimeTypeUsed', usage1.isRuntimeTypeUsed,
       usage2.isRuntimeTypeUsed);
   check(usage1, usage2, 'isIsolateInUse', usage1.isIsolateInUse,
       usage2.isIsolateInUse);
   check(usage1, usage2, 'isFunctionApplyUsed', usage1.isFunctionApplyUsed,
       usage2.isFunctionApplyUsed);
   check(usage1, usage2, 'isNoSuchMethodUsed', usage1.isNoSuchMethodUsed,
       usage2.isNoSuchMethodUsed);
 }