Fixes #1673: ensure instance effects exist before marshaling attributes.

Author: Steven Orvell

polymer.html

@@ -71,12 +71,12 @@
       this._popHost();
       // concretize template references
       this._marshalAnnotationReferences();
-      // install host attributes
-      this._marshalHostAttributes();
       // setup debouncers
       this._setupDebouncers();
       // concretize effects on instance
       this._marshalInstanceEffects();
+      // install host attributes
+      this._marshalHostAttributes();
       // acquire instance behaviors
       this._marshalBehaviors();
       // acquire initial instance attribute values