Adding 'part of html' to all files which are used by dart:html.

sdk/lib/html/src/Serialization.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.
 
 // Patch file for the dart:isolate library.
 
+part of html;
+
 /********************************************************
   Inserted from lib/isolate/serialization.dart
  ********************************************************/
 
 class _MessageTraverserVisitedMap {
 
   operator[](var object) => null;
   void operator[]=(var object, var info) { }
 
   void reset() { }
@@ skipping 187 matching lines @@
   }
 
   abstract deserializeSendPort(List x);
 
   deserializeObject(List x) {
     // TODO(floitsch): Use real exception (which one?).
     throw "Unexpected serialized object";
   }
 }