Revert r13569 "Automagically start up selenium server for Safari." Seems to be

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 1088 matching lines @@
         }
         if (!_isSeleniumAvailable) {
           _startSeleniumServer();
         }
       };
     }
   }
 
   void _runTest(TestCase test) {
     if (test.usesWebDriver) {
-      browserUsed = test.configuration['runtime'];
+      browserUsed = test.configuration['browser'];
       if (_needsSelenium) _ensureSeleniumServerRunning();
     }
     _progress.testAdded();
     _tests.add(test);
     _tryRunTest();
   }
 
   /**
    * Monitor the output of the Selenium server, to know when we are ready to
    * begin running tests.
@@ skipping 127 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++;
     }
   }
 }