Fix bug in refactoring of string concatenations in test code.

tools/testing/dart/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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 1079 matching lines @@
     throw new Exception('Unable to find inactive batch runner.');
   }
 
   void _tryRunTest() {
     _checkDone();
     if (_numProcesses < _maxProcesses && !_tests.isEmpty()) {
       TestCase test = _tests.removeFirst();
       if (_listTests) {
         var fields = [test.displayName,
                       Strings.join(new List.from(test.expectedOutcomes), ','),
-                      test.isNegative];
+                      test.isNegative.toString()];
         fields.addAll(test.commands.last().arguments);
         print(Strings.join(fields, '\t'));
         return;
       }
       if (test.usesWebDriver && _needsSelenium && !_isSeleniumAvailable) {
         // The server is not ready to run Selenium tests. Put the test back in
         // the queue.  Avoid spin-polling by using a timeout.
         _tests.add(test);
         new Timer(1000, (timer) {_tryRunTest();});  // Don't lose a process.
         return;
@@ skipping 25 matching lines @@
         // the developer doesn't waste his or her time trying to fix a bunch of
         // tests that appear to be broken but were actually just flakes that
         // didn't get retried because there had already been one failure.
         bool allowRetry = _MAX_FAILED_NO_RETRY > _progress.numFailedTests;
         new RunningProcess(test, allowRetry, this).start();
       }
       _numProcesses++;
     }
   }
 }