Add constructors to all the event classes.

client/html/generated/src/wrapping/_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) {}
-
-  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;
-  }
-}