Removed Polymer from Observatory deps

packages/web_components/test/custom_element_proxy_test.dart

 // Copyright (c) 2015, 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.
+@TestOn('browser')
 library custom_element_proxy_test;
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:js';
-import 'package:unittest/html_config.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 import 'package:web_components/web_components.dart';
 
 @CustomElementProxy('basic-element')
 class BasicElement extends HtmlElement {
   BasicElement.created() : super.created();
 
   factory BasicElement() => document.createElement('basic-element');
 
   bool get isBasicElement =>
       new JsObject.fromBrowserObject(this)['isBasicElement'];
 }
 
 @CustomElementProxy('extended-element', extendsTag: 'input')
 class ExtendedElement extends InputElement {
   ExtendedElement.created() : super.created();
 
   factory ExtendedElement() =>
       document.createElement('input', 'extended-element');
 
   bool get isExtendedElement =>
       new JsObject.fromBrowserObject(this)['isExtendedElement'];
 }
 
 main() {
-  useHtmlConfiguration();
-  initWebComponents().then((_) {
+  return initWebComponents().then((_) {
     var container = querySelector('#container') as DivElement;
 
     tearDown(() {
       container.children.clear();
     });
 
     test('basic custom element', () {
       container.append(new BasicElement());
-      container.appendHtml('<basic-element></basic_element>');
+      container.appendHtml('<basic-element></basic_element>',
+          treeSanitizer: nullSanitizer);
       // TODO(jakemac): after appendHtml elements are upgraded asynchronously,
       // why? https://github.com/dart-lang/web-components/issues/4
       return new Future(() {}).then((_) {
         var elements = container.querySelectorAll('basic-element');
         expect(elements.length, 2);
         for (BasicElement element in elements) {
-          print(element.outerHtml);
-          print(element.runtimeType);
           expect(element.isBasicElement, isTrue);
         }
       });
     });
 
     test('extends custom element', () {
       container.append(new ExtendedElement());
-      container.appendHtml('<input is="extended-element" />');
+      container.appendHtml('<input is="extended-element" />',
+          treeSanitizer: nullSanitizer);
       // TODO(jakemac): after appendHtml elements are upgraded asynchronously,
       // why? https://github.com/dart-lang/web-components/issues/4
       return new Future(() {}).then((_) {
         var elements = container.querySelectorAll('input');
         expect(elements.length, 2);
         for (ExtendedElement element in elements) {
           expect(element.isExtendedElement, isTrue);
         }
       });
     });
   });
 }
+
+class NullTreeSanitizer implements NodeTreeSanitizer {
+  const NullTreeSanitizer();
+  void sanitizeTree(Node node) {}
+}
+
+final nullSanitizer = const NullTreeSanitizer();