Add runtime=dartium webdriver support to test.dart

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 118 matching lines @@
     final mode = configuration['mode'];
     final arch = configuration['arch'];
     return "$compiler-$runtime ${mode}_$arch";
   }
 
   List<String> get batchRunnerArguments() => ['-batch'];
   List<String> get batchTestArguments() => commands.last().arguments;
 
   void completed() { completedHandler(this); }
 
-  bool get usesWebDriver() => (const ['chrome', 'ff', 'safari', 'ie', 'opera'])
+  bool get usesWebDriver() => (const ['chrome', 'dartium', 'ff', 'safari',
+                                      'ie', 'opera'])
       .indexOf(configuration['runtime']) >= 0;
 }
 
 
 /**
  * BrowserTestCase has an extra compilation command that is run in a separate
  * process, before the regular test is run as in the base class [TestCase].
  * If the compilation command fails, then the rest of the test is not run.
  */
 class BrowserTestCase extends TestCase {
@@ skipping 991 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++;
     }
   }
 }