Cleaning up event constructors

tests/html/wheelevent_test.dart

 // Copyright (c) 2013, 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.
 
 library wheel_event_test;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
 
 
@@ skipping 18 matching lines @@
   }
 
   test('wheelEvent', () {
     var element = new DivElement();
     element.on.mouseWheel.add(expectAsync1((e) {
       expect(e.screenX, 100);
       expect(e.deltaX, 0);
       expect(e.deltaY, 240);
     }));
     var event = new WheelEvent(wheelEvent,
-      window,
-      0,
-      240,
-      0,
-      100,
-      200,
-      10,
-      20,
-      0);
+      deltaX: 0,
+      deltaY: 240,
+      screenX: 100);
     element.$dom_dispatchEvent(event);
   });
 
   test('wheelEvent Stream', () {
     var element = new DivElement();
     element.onMouseWheel.listen(expectAsync1((e) {
       expect(e.screenX, 100);
       expect(e.deltaX, 0);
       expect(e.deltaY, 240);
     }));
     var event = new WheelEvent(wheelEvent,
-      window,
-      0,
-      240,
-      0,
-      100,
-      200,
-      10,
-      20,
-      0);
+      deltaX: 0,
+      deltaY: 240,
+      screenX: 100);
     element.$dom_dispatchEvent(event);
   });
 }