Merge WorldImpl with ResolutionWorldBuilderImpl

tests/compiler/dart2js/kernel/closed_world_test.dart

Index: tests/compiler/dart2js/kernel/closed_world_test.dart
diff --git a/tests/compiler/dart2js/kernel/closed_world_test.dart b/tests/compiler/dart2js/kernel/closed_world_test.dart
index 60a4505f27ac79915929f0baec8d4f1aefb4c816..c51d57c4f8b6337a4960337d6e106afd96ef1180 100644
--- a/tests/compiler/dart2js/kernel/closed_world_test.dart
+++ b/tests/compiler/dart2js/kernel/closed_world_test.dart
@@ -80,7 +80,7 @@ main(List<String> args) {
     worldBuilder.useInstantiationMap = true;
     compiler.resolution.retainCachesForTesting = true;
     await compiler.run(entryPoint);
-    compiler.resolverWorld.openWorld.closeWorld(compiler.reporter);
+    compiler.resolverWorld.closeWorld(compiler.reporter);
 
     JavaScriptBackend backend = compiler.backend;
     // Create a new resolution enqueuer and feed it with the [WorldImpact]s
@@ -114,8 +114,7 @@ main(List<String> args) {
           .transformResolutionImpact(enqueuer, resolutionImpact);
       enqueuer.applyImpact(worldImpact, impactSource: element);
     });
-    ClosedWorld closedWorld =
-        enqueuer.universe.openWorld.closeWorld(compiler.reporter);
+    ClosedWorld closedWorld = enqueuer.universe.closeWorld(compiler.reporter);
 
     checkResolutionEnqueuers(compiler.enqueuer.resolution, enqueuer,
         typeEquivalence: (DartType a, DartType b) {