Some fixes in unittest after io v2

pkg/unittest/lib/html_config.dart

 // Copyright (c) 2011, 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.
 
 /**
  * A simple unit test library for running tests in a browser.
  */
 library unittest_html_config;
 
 import 'dart:async';
 import 'dart:html';
 import 'unittest.dart';
 
 /** Creates a table showing tests results in HTML. */
 void _showResultsInPage(int passed, int failed, int errors,
     List<TestCase> results, bool isLayoutTest, String uncaughtError) {
   if (isLayoutTest && (passed == results.length) && uncaughtError == null) {
     document.body.innerHtml = "PASS";
   } else {
     var newBody = new StringBuffer();
-    newBody.add("<table class='unittest-table'><tbody>");
-    newBody.add(passed == results.length && uncaughtError == null
+    newBody.write("<table class='unittest-table'><tbody>");
+    newBody.write(passed == results.length && uncaughtError == null
         ? "<tr><td colspan='3' class='unittest-pass'>PASS</td></tr>"
         : "<tr><td colspan='3' class='unittest-fail'>FAIL</td></tr>");
 
     for (final test_ in results) {
-      newBody.add(_toHtml(test_));
+      newBody.write(_toHtml(test_));
     }
 
     if (uncaughtError != null) {
-        newBody.add('''<tr>
+        newBody.write('''<tr>
           <td>--</td>
           <td class="unittest-error">ERROR</td>
           <td>Uncaught error: $uncaughtError</td>
         </tr>''');
     }
 
     if (passed == results.length && uncaughtError == null) {
-      newBody.add("""
+      newBody.write("""
           <tr><td colspan='3' class='unittest-pass'>
             All ${passed} tests passed
           </td></tr>""");
     } else {
-      newBody.add("""
+      newBody.write("""
           <tr><td colspan='3'>Total
             <span class='unittest-pass'>${passed} passed</span>,
             <span class='unittest-fail'>${failed} failed</span>
             <span class='unittest-error'>
             ${errors + (uncaughtError == null ? 0 : 1)} errors</span>
           </td></tr>""");
     }
-    newBody.add("</tbody></table>");
+    newBody.write("</tbody></table>");
     document.body.innerHtml = newBody.toString();
   }
 }
 
 String _toHtml(TestCase test_) {
   if (!test_.isComplete) {
     return '''
         <tr>
           <td>${test_.id}</td>
           <td class="unittest-error">NO STATUS</td>
@@ skipping 74 matching lines @@
   void onDone(bool success) {
     _uninstallHandlers();
     window.postMessage('unittest-suite-done', '*');
   }
 }
 
 void useHtmlConfiguration([bool isLayoutTest = false]) {
   if (config != null) return;
   configure(new HtmlConfiguration(isLayoutTest));
 }