webui fixes for 0.8.9

test/data/input/bind_hyphenated_attribute_test.html

Index: test/data/input/bind_hyphenated_attribute_test.html
diff --git a/test/data/input/bind_hyphenated_attribute_test.html b/test/data/input/bind_hyphenated_attribute_test.html
index 6bdc3d2f8fcc40d584c7d8d7e0b5230dbcc1ca13..963b340e8c6480b007e7dbc5d7d13ce77283ce59 100644
--- a/test/data/input/bind_hyphenated_attribute_test.html
+++ b/test/data/input/bind_hyphenated_attribute_test.html
@@ -14,6 +14,8 @@
   <div data-hi="{{topLevelVar}}"></div>
   <script type="application/dart">
     import 'dart:html';
+    import 'package:web_ui/web_ui.dart';
+    
     @observable String topLevelVar = "hi";
     main() {
       window.onLoad.listen((e) {