Remove temp code to ignore "--failure-summary".

tools/testing/dart/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.
 
 import 'dart:io';
 
 import 'configuration.dart';
 import 'drt_updater.dart';
 import 'path.dart';
 import 'test_suite.dart';
@@ skipping 312 matching lines @@
     'write_test_outcome_log',
   ].toSet();
 
   /// Parses a list of strings as test options.
   ///
   /// Returns a list of configurations in which to run the tests.
   /// Configurations are maps mapping from option keys to values. When
   /// encountering the first non-option string, the rest of the arguments are
   /// stored in the returned Map under the 'rest' key.
   List<Configuration> parse(List<String> arguments) {
-    // TODO(rnystrom): The builders on the buildbots still pass this even
-    // though it does nothing. Until those can be fixed, silently ignore the
-    // option. Remove this once the buildbot scripts are fixed.
-    if (arguments.contains("--failure-summary")) {
-      arguments = arguments.where((arg) => arg != "--failure-summary").toList();
-      print('Note: Ignoring unsupported "--failure-summary" option.');
-    }
-
     var configuration = <String, dynamic>{};
 
     // Fill in configuration with arguments passed to the test script.
     for (var i = 0; i < arguments.length; i++) {
       var arg = arguments[i];
 
       // Help supersedes all other arguments.
       if (arg == "--help" || arg == "-h") {
         _printHelp();
         return null;
@@ skipping 427 matching lines @@
       if (name == option.name) return option;
 
       // Allow hyphens instead of underscores as the separator since they are
       // more common for command line flags.
       if (name == option.name.replaceAll("_", "-")) return option;
     }
 
     return null;
   }
 }