Removed Polymer from Observatory deps

packages/web_components/test/init_web_components_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.
 @initializeTracker
+@TestOn('browser')
 library web_components.test.init_web_components_test;
 
-import 'package:unittest/html_config.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 import 'package:initialize/initialize.dart' show LibraryIdentifier;
 import 'package:initialize/src/initialize_tracker.dart';
 import 'package:web_components/web_components.dart';
 
 const String importPath = 'my_import.html';
 
 main() {
-  useHtmlConfiguration();
-
   test('can initialize scripts from html imports', () {
     return initWebComponents().then((_) {
       var expectedInitializers = [
         const LibraryIdentifier(
             #web_components.test.deps.b, null, 'deps/b.dart'),
         // This one changes based on deploy mode because its an inline script.
-        const LibraryIdentifier(#web_components.test.deps.c, null, deployMode
-            ? 'init_web_components_test.html.0.dart'
-            : 'deps/c.html'),
+        const LibraryIdentifier(
+            #web_components.test.deps.c,
+            null,
+            deployMode
+                ? 'init_web_components_test.html.0.dart'
+                : 'deps/c.html'),
         const LibraryIdentifier(
             #web_components.test.deps.a, null, 'deps/a.dart'),
         const LibraryIdentifier(#web_components.test.init_web_components_test,
             null, 'init_web_components_test.dart'),
       ];
       expect(InitializeTracker.seen, expectedInitializers);
     });
   });
 }