Add constructors to all the event classes.

client/html/src/StorageEventWrappingImplementation.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.
+
+class StorageEventWrappingImplementation extends EventWrappingImplementation implements StorageEvent {
+  StorageEventWrappingImplementation._wrap(ptr) : super._wrap(ptr);
+
+  factory StorageEventWrappingImplementation(String type, String key,
+      String url, Storage storageArea, [bool canBubble = true,
+      bool cancelable = true, String oldValue = null,
+      String newValue = null]) {
+    final e = dom.document.createEvent("StorageEvent");
+    e.initStorageEvent(type, canBubble, cancelable, key, oldValue, newValue,
+        url, LevelDom.unwrap(storageArea));
+    return LevelDom.wrapStorageEvent(e);
+  }
+
+  String get key() => _ptr.key;
+
+  String get newValue() => _ptr.newValue;
+
+  String get oldValue() => _ptr.oldValue;
+
+  Storage get storageArea() => LevelDom.wrapStorage(_ptr.storageArea);
+
+  String get url() => _ptr.url;
+}