Eliminate standalone timeout_test, pass_test, and fail_test.

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.
  */
 #library("test_runner");
 
 #import("dart:io");
-#import("dart:builtin");
 #import("status_file_parser.dart");
 #import("test_progress.dart");
 #import("test_suite.dart");
 
 final int NO_TIMEOUT = 0;
 
 /** A command executed as a step in a test case. */
 class Command {
   /** Path to the executable of this command. */
   String executable;
@@ skipping 1145 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++;
     }
   }
 }