Updated testrunner:

utils/testrunner/layout_test_runner.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 layout_test;
+
 // The filters must be set by the caller that #sources this file.
 List includeFilters;
+List excludeFilters;
 
-// TODO(gram): dart2js is not handling 'part of' properly yet; when it
-// does uncomment this.
-//part of layout_test;
-
-List excludeFilters;
+/**
+ * A special marker string used to separate group names and
+ * identify non-debug output.
+ */ 
+final marker = '###';
 
 class LayoutTestConfiguration extends unittest.Configuration {
   get autoStart => false;
   void onTestResult(unittest.TestCase testCase) {
     window.postMessage('done', '*'); // Unblock DRT
   }
 }
 
 filterTest(t) {
-  var name = t.description.replaceAll("###", " ");
+  var name = t.description.replaceAll(marker, " ");
   if (includeFilters.length > 0) {
     for (var f in includeFilters) {
       if (name.indexOf(f) >= 0) return true;
     }
     return false;
   } else if (excludeFilters.length > 0) {
     for (var f in excludeFilters) {
       if (name.indexOf(f) >= 0) return false;
     }
     return true;
   } else {
     return true;
   }
 }
 
 runTests(testMain) {
-  unittest.groupSep = '###';
-  unittest.configure(new LayoutTestConfiguration());
+  unittest.groupSep = marker;
+  unittest.unittestConfiguration = new LayoutTestConfiguration();
 
   // Create the set of test cases.
   unittest.group('', testMain);
 
   // Do any user-specified test filtering.
   unittest.filterTests(filterTest);
 
   // Filter to the test number in the search query.
   var testNum = int.parse(window.location.search.substring(6));
   if (testNum < 0 || testNum >= unittest.testCases.length) {
     print('#TEST NONEXISTENT');
     window.postMessage('done', '*'); // Unblock DRT
   } else {
     var name = unittest.testCases[testNum].description;
     print('#TEST $name');
     unittest.filterTests(name);
     // Run the test.
     print('Tests - ${unittest.testCases.length}');
     unittest.runTests();
   }
 }