Change the error handling in dart:io

tests/standalone/src/io/FileTest.dart

 // Copyright (c) 2012, 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.
 //
 // Dart test program for testing file I/O.
 
 #import("dart:io");
 #import("dart:isolate");
 
 class MyListOfOneElement implements List {
@@ skipping 828 matching lines @@
     }
     Expect.equals(true, exceptionCaught);
     Expect.equals(true, !wrongExceptionCaught);
     openedFile.closeSync();
     file.deleteSync();
   }
 
   static void testOpenDirectoryAsFile() {
     var f = new File('.');
     f.open(FileMode.READ, (r) => Expect.fail('Directory opened as file'));
+    f.onError = (e) => null;
   }
 
   static void testOpenDirectoryAsFileSync() {
     var f = new File('.');
     try {
       f.openSync();
       Expect.fail("Expected exception opening directory as file");
     } catch (var e) {
       Expect.isTrue(e is FileIOException);
     }
@@ skipping 219 matching lines @@
       testWriteVariousLists();
       testDirectory();
       testDirectorySync();
     });
   }
 }
 
 main() {
   FileTest.testMain();
 }