Further reduce use of Compiler.closedWorld.

tests/compiler/dart2js/map_tracer_test.dart

 // Copyright (c) 2014, 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.
 
 import 'package:expect/expect.dart';
 import "package:async_helper/async_helper.dart";
 import 'package:compiler/src/types/types.dart' show MapTypeMask, TypeMask;
 
 import 'compiler_helper.dart';
 import 'type_mask_test_helper.dart';
@@ skipping 194 matching lines @@
   doTest('{presetKey : anInt}', "presetKey", "anInt");
   // Test preset map of <Double,uint32>
   doTest('{aDouble : anInt}', "aDouble", "anInt");
 }
 
 void doTest(String allocation, [String keyElement, String valueElement]) {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(generateTest(allocation), uri,
       expectedErrors: 0, expectedWarnings: 1);
   compiler.closeResolution();
-  var closedWorld = compiler.closedWorld;
   asyncTest(() => compiler.run(uri).then((_) {
         var keyType, valueType;
-        var commonMasks = compiler.closedWorld.commonMasks;
         var typesInferrer = compiler.globalInference.typesInferrerInternal;
+        var closedWorld = typesInferrer.closedWorld;
+        var commonMasks = closedWorld.commonMasks;
         var emptyType = new TypeMask.nonNullEmpty();
         var aKeyType =
             typesInferrer.getTypeOfElement(findElement(compiler, 'aKey'));
         if (keyElement != null) {
           keyType =
               typesInferrer.getTypeOfElement(findElement(compiler, keyElement));
         }
         if (valueElement != null) {
           valueType = typesInferrer
               .getTypeOfElement(findElement(compiler, valueElement));
         }
         if (keyType == null) keyType = emptyType;
         if (valueType == null) valueType = emptyType;
 
         checkType(String name, keyType, valueType) {
           var element = findElement(compiler, name);
           MapTypeMask mask = typesInferrer.getTypeOfElement(element);
-          Expect.equals(keyType, simplify(mask.keyType, compiler), name);
-          Expect.equals(valueType, simplify(mask.valueType, compiler), name);
+          Expect.equals(keyType, simplify(mask.keyType, closedWorld), name);
+          Expect.equals(valueType, simplify(mask.valueType, closedWorld), name);
         }
 
         K(TypeMask other) =>
-            simplify(keyType.union(other, closedWorld), compiler);
+            simplify(keyType.union(other, closedWorld), closedWorld);
         V(TypeMask other) =>
-            simplify(valueType.union(other, closedWorld), compiler).nullable();
+            simplify(valueType.union(other, closedWorld), closedWorld)
+                .nullable();
 
         checkType('mapInField', K(aKeyType), V(commonMasks.numType));
         checkType('mapPassedToMethod', K(aKeyType), V(commonMasks.numType));
         checkType('mapReturnedFromMethod', K(aKeyType), V(commonMasks.numType));
         checkType('mapUsedWithCascade', K(aKeyType), V(commonMasks.numType));
         checkType('mapUsedInClosure', K(aKeyType), V(commonMasks.numType));
         checkType('mapPassedToSelector', K(aKeyType), V(commonMasks.numType));
         checkType(
             'mapReturnedFromSelector', K(aKeyType), V(commonMasks.numType));
         checkType(
@@ skipping 23 matching lines @@
         checkType('mapStoredInListButEscapes', K(commonMasks.dynamicType),
             V(commonMasks.dynamicType));
         checkType('mapStoredInMap', K(aKeyType), V(commonMasks.uint31Type));
         checkType('mapStoredInMapButEscapes', K(commonMasks.dynamicType),
             V(commonMasks.dynamicType));
 
         checkType('mapUnset', K(emptyType), V(emptyType));
         checkType('mapOnlySetWithConstraint', K(aKeyType), V(emptyType));
       }));
 }