correct syntax error.

tools/dom/src/native_DOMImplementation.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.
 
 part of html;
 
 class _Utils {
   static double dateTimeToDouble(DateTime dateTime) =>
       dateTime.millisecondsSinceEpoch.toDouble();
   static DateTime doubleToDateTime(double dateTime) {
@@ skipping 188 matching lines @@
 final _forwardingPrintClosure = _Utils.forwardingPrint;
 
  class _Timer implements Timer{
   var _canceler;
 
   _Timer(int milliSeconds, void callback(Timer timer), bool repeating) {
 
     if (repeating) {
       int id = window._setInterval(() {
         callback(this);
-      }, milliSeconds);)
+      }, milliSeconds);
       _canceler = () => window._clearInterval(id);
     } else {
       int id = window._setTimeout(() {
         _canceler = null;
         callback(this);
-      }, milliSeconds);)
+      }, milliSeconds);
       _canceler = () => window._clearTimeout(id);
     }
   }
 
   void cancel() {
     if (_canceler != null) {
       _canceler();
     }
     _canceler = null;
   }
@@ skipping 39 matching lines @@
   _send(msg) {
     _sendToHelperIsolate(msg, _sendPort);
   }
 
   bool get isActive => _isActive;
 }
 
 get _pureIsolateTimerFactoryClosure =>
     ((int milliSeconds, void callback(Timer time), bool repeating) =>
         new _PureIsolateTimer(milliSeconds, callback, repeating));