Removed Polymer from Observatory deps

packages/polymer/test/sort_registration_test.dart

-// Copyright (c) 2013, 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.
-
-library polymer.test.sort_registration_test;
-
-import 'dart:html';
-import 'package:polymer/polymer.dart';
-import 'package:unittest/html_config.dart';
-import 'package:unittest/unittest.dart';
-
-part 'sort_registration_part1.dart';
-part 'sort_registration_part2.dart';
-
-@CustomTag('x-a')
-class A extends PolymerElement {
-  A.created() : super.created();
-}
-
-main() => initPolymer().then((zone) => zone.run(() {
-  useHtmlConfiguration();
-  setUp(() => Polymer.onReady);
-
-  test('registration is done in the right order', () {
-    expect(querySelector('x-e') is E, isTrue);
-  });
-}));