Wrapping leaf nodes in non polymer elements

runtime/observatory/lib/src/repositories/mocks/error.dart

Index: runtime/observatory/lib/src/repositories/mocks/error.dart
diff --git a/runtime/observatory/lib/src/repositories/mocks/error.dart b/runtime/observatory/lib/src/repositories/mocks/error.dart
new file mode 100644
index 0000000000000000000000000000000000000000..a8b84bb5430223a8ada7681e0883587db04fa3b8
--- /dev/null
+++ b/runtime/observatory/lib/src/repositories/mocks/error.dart
@@ -0,0 +1,19 @@
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file
+
+part of repositories;
+
+class ErrorRefMock implements ErrorRef {
+  final String id;
+  final ErrorKind kind;
+  final String message;
+  ErrorRefMock({this.id, this.kind, this.message});
+}
+
+class ErrorMock implements Error {
+  final String id;
+  final ErrorKind kind;
+  final String message;
+  ErrorMock({this.id, this.kind, this.message});
+}