Hook up the dartdoc tests to test.py, test.dart, and frog/presubmit.py.

tools/testing/dart/test_options.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.
 
 #library("test_options_parser");
 
 List<String> defaultTestSelectors =
     const ['dartc', 'samples', 'standalone', 'corelib', 'co19', 'language',
-           'isolate', 'stub-generator', 'vm', 'client'];
+           'isolate', 'stub-generator', 'vm', 'client', 'dartdoc'];
 
 /**
  * Specification of a single test option.
  *
  * The name of the specification is used as the key for the option in
  * the Map returned from the [TestOptionParser] parse method.
  */
 class _TestOptionSpecification {
   _TestOptionSpecification(this.name,
                            this.description,
@@ skipping 445 matching lines @@
         return option;
       }
     }
     print('Unknown test option $name');
     exit(1);
   }
 
 
   List<_TestOptionSpecification> _options;
 }