Add Dartdoc testing to pub bots.

tools/test.dart

 #!/usr/bin/env 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.
 
 /**
  * This file is the entrypoint of the dart test suite.  This suite is used
  * to test:
  *
  *     1. the dart vm
@@ skipping 48 matching lines @@
     new Path('tests/html'),
     new Path('tests/isolate'),
     new Path('tests/json'),
     new Path('tests/language'),
     new Path('tests/lib'),
     new Path('tests/standalone'),
     new Path('tests/utils'),
     new Path('utils/tests/css'),
     new Path('utils/tests/peg'),
     new Path('utils/tests/pub'),
+    new Path('sdk/lib/_internal/dartdoc'),
 ];
 
 main() {
   var startTime = new Date.now();
   var optionsParser = new TestOptionsParser();
   List<Map> configurations = optionsParser.parse(new Options().arguments);
   if (configurations == null || configurations.length == 0) return;
 
   // Extract global options from first configuration.
   var firstConf = configurations[0];
@@ skipping 91 matching lines @@
   new ProcessQueue(maxProcesses,
                    maxBrowserProcesses,
                    progressIndicator,
                    startTime,
                    printTiming,
                    testSuites,
                    allTestsFinished,
                    verbose,
                    listTests);
 }