Add support for SDK outline in KernelDriver.

pkg/front_end/test/memory_file_system_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.
 // SharedOptions=--supermixin
 
 library front_end.test.memory_file_system_test;
 
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ skipping 26 matching lines @@
     file = entityForPath(path);
   }
 
   test_createDirectory_doesNotExist() async {
     file.createDirectory();
     expect(await file.exists(), true);
   }
 
   test_createDirectory_exists_asDirectory() async {
     file.createDirectory();
-    expect(() => file.createDirectory(), _throwsFileSystemException);
+    file.createDirectory();
+    expect(await file.exists(), true);
   }
 
   test_createDirectory_exists_asFile() async {
     file.writeAsStringSync('');
     expect(() => file.createDirectory(), _throwsFileSystemException);
   }
 
   test_equals_differentPaths() {
     expect(file == entityForPath(join(tempPath, 'file2.txt')), isFalse);
   }
@@ skipping 241 matching lines @@
   String tempPath;
 
   String join(String path1, String path2, [String path3, String path4]) =>
       pathos.windows.join(path1, path2, path3, path4);
 
   void setUp() {
     tempPath = r'c:\test_file_system';
     fileSystem = new MemoryFileSystem(Uri.parse('file:///c:/cwd'));
   }
 }