Further reduce use of Compiler.closedWorld.

tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart

Index: tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart
diff --git a/tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart b/tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart
index 01a896a1b8d6a52ab08b1c9770bd1a38a4069347..35969e1ea2795d99aab4cd0a3674f427c73bb3a0 100644
--- a/tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart
+++ b/tests/compiler/dart2js/simple_inferrer_global_field_closure2_test.dart
@@ -29,6 +29,7 @@ void main() {
   var compiler = compilerFor(TEST, uri);
   asyncTest(() => compiler.run(uri).then((_) {
         var typesInferrer = compiler.globalInference.typesInferrerInternal;
+        var closedWorld = typesInferrer.closedWorld;
 
         checkArgument(String functionName, type) {
           var functionElement = findElement(compiler, functionName);
@@ -36,10 +37,10 @@ void main() {
           var element = signature.requiredParameters.first;
           Expect.equals(
               type,
-              simplify(typesInferrer.getTypeOfElement(element), compiler),
+              simplify(typesInferrer.getTypeOfElement(element), closedWorld),
               functionName);
         }
 
-        checkArgument('method', compiler.closedWorld.commonMasks.uint31Type);
+        checkArgument('method', closedWorld.commonMasks.uint31Type);
       }));
 }