Fixing up setting styles to invalidate on IE9.

lib/html/dartium/html_dartium.dart

Index: lib/html/dartium/html_dartium.dart
diff --git a/lib/html/dartium/html_dartium.dart b/lib/html/dartium/html_dartium.dart
index 804f70d5dfebfd2a5b741f942daccdafb46a6333..5cb73ad97dc5175a2a49f4359de9311d7d315fc5 100644
--- a/lib/html/dartium/html_dartium.dart
+++ b/lib/html/dartium/html_dartium.dart
@@ -3632,6 +3632,8 @@ class _CSSStyleDeclarationImpl extends NativeFieldWrapperClass1 implements CSSSt
   void set zoom(var value) {
     setProperty('zoom', value, '');
   }
+
+  void setProperty(String propertyName, String value, [String priority]) native "CSSStyleDeclaration_setProperty_Callback";
 }
 // 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