Changed buildbot annotated steps to run tests on ARM device

tools/testing/dart/test_options.dart

 // Copyright (c) 2013, 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.
 
 library test_options_parser;
 
 import "dart:io";
 import "dart:math";
 import "drt_updater.dart";
 import "test_suite.dart";
@@ skipping 95 matching lines @@
           tests).''',
               ['-r', '--runtime'],
               ['vm', 'd8', 'jsshell', 'drt', 'dartium', 'ff', 'firefox',
                'chrome', 'safari', 'ie9', 'ie10', 'opera', 'chromeOnAndroid',
                'none'],
               'vm'),
           new _TestOptionSpecification(
               'arch',
               'The architecture to run tests for',
               ['-a', '--arch'],
-              ['all', 'ia32', 'x64', 'simarm', 'simmips'],
+              ['all', 'ia32', 'x64', 'simarm', 'simmips', 'arm'],
               'ia32'),
           new _TestOptionSpecification(
               'system',
               'The operating system to run tests on',
               ['-s', '--system'],
               ['linux', 'macos', 'windows'],
               Platform.operatingSystem),
           new _TestOptionSpecification(
               'checked',
               'Run tests in checked mode',
@@ skipping 595 matching lines @@
         return option;
       }
     }
     print('Unknown test option $name');
     exit(1);
   }
 
 
   List<_TestOptionSpecification> _options;
 }