Further reduce use of Compiler.closedWorld.

tests/compiler/dart2js/mirror_final_field_inferrer_test.dart

Index: tests/compiler/dart2js/mirror_final_field_inferrer_test.dart
diff --git a/tests/compiler/dart2js/mirror_final_field_inferrer_test.dart b/tests/compiler/dart2js/mirror_final_field_inferrer_test.dart
index 78ea48799e99a81d93eecd72b095706d51297532..0934e37f23be951b3c963bb44cf2fe920fef5565 100644
--- a/tests/compiler/dart2js/mirror_final_field_inferrer_test.dart
+++ b/tests/compiler/dart2js/mirror_final_field_inferrer_test.dart
@@ -28,9 +28,12 @@ void main() {
     var result = await runCompiler(memorySourceFiles: MEMORY_SOURCE_FILES);
     var compiler = result.compiler;
     var element = findElement(compiler, 'field');
-    var commonMasks = compiler.closedWorld.commonMasks;
     var typesInferrer = compiler.globalInference.typesInferrerInternal;
-    Expect.equals(commonMasks.uint31Type,
-        simplify(typesInferrer.getTypeOfElement(element), compiler), 'field');
+    var closedWorld = typesInferrer.closedWorld;
+    var commonMasks = closedWorld.commonMasks;
+    Expect.equals(
+        commonMasks.uint31Type,
+        simplify(typesInferrer.getTypeOfElement(element), closedWorld),
+        'field');
   });
 }