Refactoring of ProgressIndicator

tests/standalone/io/test_runner_exit_code_test.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.
-
-import "dart:io";
-
-void runTests(String executable, String script, Iterator iterator) {
-  if (iterator.moveNext()) {
-    var progressIndicator = iterator.current;
-    Process.run(executable, [script, progressIndicator]).then((result) {
-      Expect.equals(1, result.exitCode);
-      if (progressIndicator == 'buildbot') {
-        Expect.isTrue(result.stdout.contains("@@@STEP_FAILURE@@@"));
-      }
-      runTests(executable, script, iterator);
-    });
-  }
-}
-
-main() {
-  var scriptPath = new Path(new Options().script);
-  var scriptDirPath = scriptPath.directoryPath;
-  var exitCodeScriptPath =
-    scriptDirPath.append('test_runner_exit_code_script.dart');
-  var script = exitCodeScriptPath.toNativePath();
-  var executable = new Options().executable;
-  var progressTypes = ['compact', 'color', 'line', 'verbose',
-                       'status', 'buildbot'];
-  var iterator = progressTypes.iterator;
-  runTests(executable, script, iterator);
-}