Add method to html_dartium utils to check for NSM errors

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 171 matching lines @@
   /**
    * Removes the trailing dot from an expression ending in a dot.
    * This method is used as Library prefixes include a trailing dot when using
    * the C Dart debugger API.
    */
   static String stripTrailingDot(String str) =>
     (str != null && str[str.length - 1] == '.') ? str.substring(0, str.length - 1) : str;
 
   static String addTrailingDot(String str) => '${str}.';
 
+  static bool isNoSuchMethodError(obj) => obj is NoSuchMethodError;
+
   // TODO(jacobr): we need a failsafe way to determine that a Node is really a
   // DOM node rather than just a class that extends Node.
   static bool isNode(obj) => obj is Node;
 }
 
 class _NPObject extends NativeFieldWrapperClass1 {
   _NPObject.internal();
   static _NPObject retrieve(String key) native "NPObject_retrieve";
   property(String propertyName) native "NPObject_property";
   invoke(String methodName, [List args = null]) native "NPObject_invoke";
@@ skipping 184 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));