[Samples]: Fixed sample code in widget theming.

Author: dglazkov

samples/widget-theming.html

@@ -78,6 +78,7 @@ <h1>Widget Theming</h1>
         <ins>var style = document.createElement('style');</ins>
         <ins>style.scoped = true;</ins>
         <ins>style.textContent = this.scopedStyleText;</ins>
+        <ins>shadow.appendChild(style);</ins>
         var users = shadow.appendChild(document.createElement('ul'));
         this.loadUsers(MAX_USERS, function(user) {
             var li = document.createElement('li');