Remove Compiler.openWorld

tests/compiler/dart2js/map_tracer_test.dart

Index: tests/compiler/dart2js/map_tracer_test.dart
diff --git a/tests/compiler/dart2js/map_tracer_test.dart b/tests/compiler/dart2js/map_tracer_test.dart
index 571450cca63239ae95a101c7439ce2b9fc6dd78d..0bd52891b454d41e11a5b30ce8c33c7c212ed8f2 100644
--- a/tests/compiler/dart2js/map_tracer_test.dart
+++ b/tests/compiler/dart2js/map_tracer_test.dart
@@ -211,7 +211,8 @@ void doTest(String allocation, [String keyElement, String valueElement]) {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(generateTest(allocation), uri,
       expectedErrors: 0, expectedWarnings: 1);
-  var closedWorld = compiler.openWorld.closeWorld(compiler.reporter);
+  compiler.closeResolution();
+  var closedWorld = compiler.closedWorld;
   asyncTest(() => compiler.run(uri).then((_) {
         var keyType, valueType;
         var commonMasks = compiler.closedWorld.commonMasks;