fix webui for sdk 0.8.7

test/run_all.dart

 // Copyright (c) 2012, 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.
 
 /**
  * This is a helper for run.sh. We try to run all of the Dart code in one
  * instance of the Dart VM to reduce warm-up time.
  */
 library run_impl;
 
 import 'dart:async';
 import 'dart:io';
-import 'dart:isolate';
 import 'dart:math' show min;
 import 'dart:utf' show encodeUtf8;
 import 'package:pathos/path.dart' as path;
 import 'package:unittest/compact_vm_config.dart';
 import 'package:unittest/unittest.dart';
 import 'package:web_ui/dwc.dart' as dwc;
 import 'package:web_ui/testing/render_test.dart';
 
 import 'analyzer_test.dart' as analyzer_test;
 import 'css_test.dart' as css_test;
@@ skipping 78 matching lines @@
       arguments: args, pattern: pattern, deleteDir: deleteDirectory);
 }
 
 void cssCompileShadowDOMTest(String path, String pattern,
     [bool deleteDirectory = true]) {
   var args = ['--no-css'];
   renderTests(path, path, '$path/expected', '$path/out',
       arguments: args, pattern: pattern,
       deleteDir: deleteDirectory);
 }