"Reverting 18531"

tests/html/window_open_test.dart

Index: tests/html/window_open_test.dart
diff --git a/tests/html/window_open_test.dart b/tests/html/window_open_test.dart
index 23baef4603a7822357de0b07056a1696c4283e0b..8fbe664ba32c837decf73cbf6d3a6049fa7f8427 100644
--- a/tests/html/window_open_test.dart
+++ b/tests/html/window_open_test.dart
@@ -2,7 +2,6 @@ library WindowOpenTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
-import 'dart:async';
 
 main() {
   useHtmlConfiguration();
@@ -27,8 +26,8 @@ closeWindow(win) {
   win.close();
   doneHandler() {
     if (!win.closed) {
-      new Timer(const Duration(milliseconds: 1), expectAsync0(doneHandler));
+      window.setTimeout(expectAsync0(doneHandler), 1);
     }
   }
-  new Timer(const Duration(milliseconds: 1), expectAsync0(doneHandler));
+  window.setTimeout(expectAsync0(doneHandler), 1);
 }