Removed Polymer from Observatory deps

packages/polymer/test/js_custom_event_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.web.events_test;
-
-import 'dart:html';
-import 'dart:js';
-import 'package:polymer/polymer.dart';
-import 'package:unittest/html_config.dart';
-import 'package:unittest/unittest.dart';
-
-@CustomTag('x-test')
-class XTest extends PolymerElement {
-  bool called = false;
-  XTest.created() : super.created();
-
-  void myEventHandler(e, detail, t) {
-    called = true;
-    expect(detail['value'], 42);
-  }
-}
-
-main() => initPolymer().then((zone) => zone.run(() {
-  useHtmlConfiguration();
-  setUp(() => Polymer.onReady);
-
-  test('detail on JS custom events are proxied', () {
-    var element = querySelector('x-test');
-    expect(element.called, isFalse);
-    context.callMethod('fireEvent');
-    expect(element.called, isTrue);
-  });
-}));