Move TypeMask.simplify to a test helper.

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
     '../../../sdk/lib/_internal/compiler/implementation/types/types.dart'
     show MapTypeMask, TypeMask;
 
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
+import 'type_mask_test_helper.dart';
 
 
 String generateTest(String mapAllocation) {
   return """
 int anInt = 42;
 double aDouble = 42.5;
 String aKey = 'aKey';
 String anotherKey = 'anotherKey';
 String presetKey = 'presetKey';
 
@@ skipping 206 matching lines @@
     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, mask.keyType.simplify(compiler), name);
-      Expect.equals(valueType, mask.valueType.simplify(compiler), name);
+      Expect.equals(keyType, simplify(mask.keyType, compiler), name);
+      Expect.equals(valueType, simplify(mask.valueType, compiler), name);
     }
 
-    K(TypeMask other) => keyType.union(other, compiler).simplify(compiler);
-    V(TypeMask other) => valueType.union(other, compiler).simplify(compiler);
+    K(TypeMask other) => simplify(keyType.union(other, compiler), compiler);
+    V(TypeMask other) => simplify(valueType.union(other, compiler), compiler);
 
     checkType('mapInField', K(aKeyType), V(typesTask.numType));
     checkType('mapPassedToMethod', K(aKeyType), V(typesTask.numType));
     checkType('mapReturnedFromMethod', K(aKeyType), V(typesTask.numType));
     checkType('mapUsedWithCascade', K(aKeyType), V(typesTask.numType));
     checkType('mapUsedInClosure', K(aKeyType), V(typesTask.numType));
     checkType('mapPassedToSelector', K(aKeyType), V(typesTask.numType));
     checkType('mapReturnedFromSelector', K(aKeyType), V(typesTask.numType));
     checkType('mapUsedWithConstraint', K(aKeyType), V(typesTask.uint31Type));
     checkType('mapEscapingFromSetter', K(aKeyType), V(typesTask.numType));
@@ skipping 19 matching lines @@
     checkType('mapStoredInListButEscapes', K(typesTask.dynamicType),
                                            V(typesTask.dynamicType));
     checkType('mapStoredInMap', K(aKeyType), V(typesTask.uint31Type));
     checkType('mapStoredInMapButEscapes', K(typesTask.dynamicType),
                                           V(typesTask.dynamicType));
 
     checkType('mapUnset', K(emptyType), V(emptyType));
     checkType('mapOnlySetWithConstraint', K(aKeyType), V(emptyType));
   }));
 }