big update to observe, template_binding, polymer

samples/third_party/todomvc/test/utils.dart

Index: samples/third_party/todomvc/test/utils.dart
diff --git a/samples/third_party/todomvc/test/utils.dart b/samples/third_party/todomvc/test/utils.dart
index 196ca1eac35b46e4956127b35222322f1c0ba099..3dafe562dc661b449b93d5a54c66228fbc1f93bc 100644
--- a/samples/third_party/todomvc/test/utils.dart
+++ b/samples/third_party/todomvc/test/utils.dart
@@ -12,11 +12,10 @@ Future onPropertyInit(Observable obj, String path) {
   if (obs.value != null) return new Future.value(obs.value);
 
   final c = new Completer();
-  StreamSubscription sub;
-  sub = obs.changes.listen((_) {
-    if (obs.value != null) {
-      sub.cancel();
-      c.complete(obs.value);
+  obs.open((value) {
+    if (value != null) {
+      obs.close();
+      c.complete(value);
     }
   });
   return c.future;