Consolidating platform code into dart:html_common

tools/dom/templates/html/impl/impl_WheelEvent.darttemplate

 // Copyright (c) 2012, 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.
 
 part of $LIBRARYNAME;
 
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
   factory WheelEvent(String type,
       {Window view, int deltaX: 0, int deltaY: 0,
       int detail: 0, int screenX: 0, int screenY: 0, int clientX: 0,
       int clientY: 0, int button: 0, bool canBubble: true,
       bool cancelable: true, bool ctrlKey: false, bool altKey: false,
       bool shiftKey: false, bool metaKey: false, EventTarget relatedTarget}) {
 
     if (view == null) {
       view = window;
     }
     var eventType = 'WheelEvent';
-    if (_Device.isFirefox) {
+    if (Device.isFirefox) {
       eventType = 'MouseScrollEvents';
     }
     final event = document.$dom_createEvent(eventType);
 $if DART2JS
     if (event._hasInitWheelEvent) {
       var modifiers = [];
       if (ctrlKey) {
         modifiers.push('Control');
       }
       if (altKey) {
@@ skipping 161 matching lines @@
       int deltaZ,
       int deltaMode) native;
 
 $else
   @DomName('WheelEvent.deltaX')
   num get deltaX => $dom_wheelDeltaX;
   @DomName('WheelEvent.deltaY')
   num get deltaY => $dom_wheelDeltaY;
 $endif
 }