Removed polymer & mirror from Observatory

runtime/observatory/lib/src/elements/error_ref.dart

Index: runtime/observatory/lib/src/elements/error_ref.dart
diff --git a/runtime/observatory/lib/src/elements/error_ref.dart b/runtime/observatory/lib/src/elements/error_ref.dart
index 55685ed85738fa8afc747f0ee400d6764f5f020c..8a523d3b156b534246454ab94e993c680b5dfd76 100644
--- a/runtime/observatory/lib/src/elements/error_ref.dart
+++ b/runtime/observatory/lib/src/elements/error_ref.dart
@@ -12,14 +12,14 @@ import 'package:observatory/src/elements/helpers/tag.dart';
 import 'package:observatory/src/elements/helpers/rendering_scheduler.dart';
 
 class ErrorRefElement extends HtmlElement implements Renderable {
-  static const tag = const Tag<ErrorRefElement>('error-ref-wrapped');
+  static const tag = const Tag<ErrorRefElement>('error-ref');
 
   RenderingScheduler<ErrorRefElement> _r;
 
   Stream<RenderedEvent<ErrorRefElement>> get onRendered => _r.onRendered;
 
   ErrorRef _error;
-  
+
   ErrorRef get error => _error;
 
   factory ErrorRefElement(ErrorRef error, {RenderingQueue queue}) {