Add constructors to all the event classes.

client/html/src/KeyboardEventWrappingImplementation.dart

 // Copyright (c) 2011, 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.
 
-// WARNING: Do not edit - generated code.
-
 class KeyboardEventWrappingImplementation extends UIEventWrappingImplementation implements KeyboardEvent {
   KeyboardEventWrappingImplementation._wrap(ptr) : super._wrap(ptr) {}
 
+  factory KeyboardEventWrappingImplementation(String type, Window view,
+      String keyIdentifier, int keyLocation, [bool canBubble = false,
+      bool cancelable = false, bool ctrlKey = false, bool altKey = false,
+      bool shiftKey = false, bool metaKey = false, bool altGraphKey = false]) {
+    var e = dom.document.createEvent("KeyboardEvent");
+    e.initKeyboardEvent(type, canBubble, cancelable, LevelDom.unwrap(view),
+        keyIdentifier, keyLocation, ctrlKey, altKey, shiftKey, metaKey,
+        altGraphKey);
+    return LevelDom.wrapKeyboardEvent(e);
+  }
+
   bool get altGraphKey() { return _ptr.altGraphKey; }
 
   bool get altKey() { return _ptr.altKey; }
 
   bool get ctrlKey() { return _ptr.ctrlKey; }
 
   String get keyIdentifier() { return _ptr.keyIdentifier; }
 
   int get keyLocation() { return _ptr.keyLocation; }
 
   bool get metaKey() { return _ptr.metaKey; }
 
   bool get shiftKey() { return _ptr.shiftKey; }
 
   bool getModifierState(String keyIdentifierArg) {
     return _ptr.getModifierState(keyIdentifierArg);
   }
-
-  void initKeyboardEvent(String type, bool canBubble, bool cancelable, Window view, String keyIdentifier, int keyLocation, bool ctrlKey, bool altKey, bool shiftKey, bool metaKey, bool altGraphKey) {
-    _ptr.initKeyboardEvent(type, canBubble, cancelable, LevelDom.unwrap(view), keyIdentifier, keyLocation, ctrlKey, altKey, shiftKey, metaKey, altGraphKey);
-    return;
-  }
 }