Converting tests over to using event streams.

tools/dom/templates/html/dart2js/html_dart2js.darttemplate

 // 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.
 
 // DO NOT EDIT
 // Auto-generated dart:html library.
 
 library html;
 
 import 'dart:async';
@@ skipping 29 matching lines @@
 part '$AUXILIARY_DIR/Isolates.dart';
 part '$AUXILIARY_DIR/Microtask.dart';
 part '$AUXILIARY_DIR/Serialization.dart';
 part '$AUXILIARY_DIR/shared_FactoryProviders.dart';
 part '$AUXILIARY_DIR/dart2js_Conversions.dart';
 part '$AUXILIARY_DIR/dart2js_DOMImplementation.dart';
 part '$AUXILIARY_DIR/dart2js_KeyEvent.dart';
 part '$AUXILIARY_DIR/dart2js_FactoryProviders.dart';
 part '$AUXILIARY_DIR/dart2js_LocationWrapper.dart';
 part '$AUXILIARY_DIR/dart2js_TypedArrayFactoryProvider.dart';
-part '$AUXILIARY_DIR/_Testing.dart';
 part '$AUXILIARY_DIR/_ListIterators.dart';
 
 
 Window get window => JS('Window', 'window');
 
 HtmlDocument get document => JS('Document', 'document');
 
 Element query(String selector) => document.query(selector);
 List<Element> queryAll(String selector) => document.queryAll(selector);
 
 // Workaround for tags like <cite> that lack their own Element subclass --
 // Dart issue 1990.
 class _HTMLElement extends Element native "*HTMLElement" {
 }
 
 // Support for Send/ReceivePortSync.
 int _getNewIsolateId() {
   if (JS('bool', r'!window.$dart$isolate$counter')) {
     JS('void', r'window.$dart$isolate$counter = 1');
   }
   return JS('int', r'window.$dart$isolate$counter++');
 }
 
 // Fast path to invoke JS send port.
 _callPortSync(int id, message) {
   return JS('var', r'ReceivePortSync.dispatchCall(#, #)', id, message);
 }
 
 spawnDomFunction(f) => IsolateNatives.spawnDomFunction(f);