Add factory constructor for WebSocket Add generated dom & html directories to .gitignore

client/html/src/dartium_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 _AudioContextFactoryProvider {
   factory AudioContext() => _wrap(new dom.AudioContext());
 }
 
 class _TypedArrayFactoryProvider {
 
@@ skipping 43 matching lines @@
   static Uint32Array _U32(arg) => _wrap(new dom.Uint32Array(arg));
   static Uint8ClampedArray _U8C(arg) => _wrap(new dom.Uint8ClampedArray(arg));
 
   static ensureNative(List list) => list;  // TODO: make sure.
 }
 
 class _PointFactoryProvider {
 
   factory Point(num x, num y) => _wrap(new dom.WebKitPoint(x, y));
 }
+
+class _WebSocketFactoryProvider {
+
+  factory WebSocket(String url) => _wrap(new new dom.WebSocket(url));
+}