Third round of cleanups for new optional parameter semantics.

lib/html/src/shared_FactoryProviders.dart

 // 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.
 
 class _CustomEventFactoryProvider {
   static CustomEvent createCustomEvent(String type, [bool canBubble = true,
       bool cancelable = true, Object detail = null]) {
     final _CustomEventImpl e = _document.$dom_createEvent("CustomEvent");
     e.$dom_initCustomEvent(type, canBubble, cancelable, detail);
     return e;
   }
 }
 
 class _EventFactoryProvider {
   static Event createEvent(String type, [bool canBubble = true,
       bool cancelable = true]) {
     final _EventImpl e = _document.$dom_createEvent("Event");
     e.$dom_initEvent(type, canBubble, cancelable);
     return e;
   }
 }
 
 class _MouseEventFactoryProvider {
   static MouseEvent createMouseEvent(String type, Window view, int detail,
       int screenX, int screenY, int clientX, int clientY, int button,
-      [bool canBubble = true, bool cancelable = true, bool ctrlKey = false,
-      bool altKey = false, bool shiftKey = false, bool metaKey = false,
-      EventTarget relatedTarget = null]) {
+      bool canBubble, bool cancelable, bool ctrlKey,
+      bool altKey, bool shiftKey, bool metaKey,
+      EventTarget relatedTarget) {
     final e = _document.$dom_createEvent("MouseEvent");
     e.$dom_initMouseEvent(type, canBubble, cancelable, view, detail,
         screenX, screenY, clientX, clientY, ctrlKey, altKey, shiftKey, metaKey,
         button, relatedTarget);
     return e;
   }
 }
 
 class _CSSStyleDeclarationFactoryProvider {
   static CSSStyleDeclaration createCSSStyleDeclaration_css(String css) {
@@ skipping 68 matching lines @@
 }
 
 class _SVGSVGElementFactoryProvider {
   static SVGSVGElement createSVGSVGElement() {
     final el = new SVGElement.tag("svg");
     // The SVG spec requires the version attribute to match the spec version
     el.attributes['version'] = "1.1";
     return el;
   }
 }