dart:html perf optimization based on runing Dromaeo benchmarks

lib/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 48 matching lines @@
 
 class _PointFactoryProvider {
 
   factory Point(num x, num y) => _wrap(new dom.WebKitPoint(x, y));
 }
 
 class _WebSocketFactoryProvider {
 
   factory WebSocket(String url) => _wrap(new dom.WebSocket(url));
 }
+
+class _TextFactoryProvider {
+  factory Text(String data) => _document.$dom_createTextNode(data);
+}