Plugin config cleanup.

pkg/analyzer/test/src/plugin/plugin_config_test.dart

 // Copyright (c) 2015, 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.src.plugin.plugin_config_test;
 
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/src/plugin/plugin_configuration.dart';
 import 'package:unittest/unittest.dart';
 import 'package:yaml/yaml.dart';
@@ skipping 27 matching lines @@
         expect(plugins[2].className, equals('MyPlugin'));
       });
       test('plugin map (empty)', () {
         const optionsSrc = '''
 analyzer:
   plugins:
     # my_plugin1: ^0.1.0 #shorthand 
 ''';
         var config = parseConfig(optionsSrc);
         // Commented out plugins shouldn't cause a parse failure.
-        expect(config.plugins.toList(), hasLength(0));
+        expect(config.plugins, hasLength(0));
       });
       group('errors', () {
         test('bad format', () {
           const optionsSrc = '''
 analyzer:
   plugins:
     - my_plugin1
     - my_plugin2
 ''';
           try {
@@ skipping 12 matching lines @@
   });
 }
 
 PluginConfig parseConfig(String optionsSrc) {
   var options = new AnalysisOptionsProvider().getOptionsFromString(optionsSrc);
   return new PluginConfig.fromOptions(options);
 }
 
 List<PluginInfo> pluginsSortedByName(PluginConfig config) =>
     config.plugins.toList()..sort((p1, p2) => p1.name.compareTo(p2.name));