Round Touch attributes back to int for backwards compatibility

sdk/lib/_blink/dartium/_blink_dartium.dart

 /**
  * This library provides entry points to the native Blink code which backs
  * up the dart:html library.
  */
 library dart.dom._blink;
 
 // Copyright (c) 2014, 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.
 
@@ skipping 8365 matching lines @@
   // _DOMStringMap native entry  points
   static containsKey(_DOMStringMap, key) native "DOMStringMap_containsKey_Callback";
 
   static item(_DOMStringMap, key) native "DOMStringMap_item_Callback";
 
   static setItem(_DOMStringMap, key, value) native "DOMStringMap_setItem_Callback";
 
   static remove(_DOMStringMap, key) native "DOMStringMap_remove_Callback";
 
   static get_keys(_DOMStringMap) native "DOMStringMap_getKeys_Callback";
-}
+}