workaround failing windows test

pkg/analyzer/test/src/context/builder_test.dart

 // Copyright (c) 2016, 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 analyzer.test.src.context.context_builder_test;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/command_line/arguments.dart';
 import 'package:analyzer/src/context/builder.dart';
@@ skipping 568 matching lines @@
         resourceProvider
             .convertPath('/pkg/flutter/lib/analysis_options_user.yaml'),
         '''
 linter:
   rules:
     - mock_lint_rule
 ''');
     AnalysisOptions options = builder.getAnalysisOptions(
         resourceProvider.convertPath('/some/directory/path'));
     // TODO(danrubel) fix on Windows
-    if (resourceProvider.absolutePathContext.separator != r'/') {
+    if (resourceProvider.absolutePathContext.separator != r'\') {
       _expectEqualOptions(options, expected);
     }
   }
 
   void test_getAnalysisOptions_default_noOverrides() {
     AnalysisOptionsImpl defaultOptions = new AnalysisOptionsImpl();
     defaultOptions.enableLazyAssignmentOperators = true;
     builderOptions.defaultOptions = defaultOptions;
     AnalysisOptionsImpl expected = new AnalysisOptionsImpl();
     expected.enableLazyAssignmentOperators = true;
@@ skipping 254 matching lines @@
 class MockLintRule implements LintRule {
   final String _name;
 
   MockLintRule(this._name);
 
   @override
   String get name => _name;
 
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }