Clean up dart:io exceptions.

sdk/lib/io/file_system_entity.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.
 
 part of dart.io;
 
 class FileSystemEntityType {
   static const FILE = const FileSystemEntityType._internal(0);
   static const DIRECTORY = const FileSystemEntityType._internal(1);
   static const LINK = const FileSystemEntityType._internal(2);
@@ skipping 353 matching lines @@
   /**
    * Synchronously checks if typeSync(path) returns
    * FileSystemEntityType.DIRECTORY.
    */
   static bool isDirectorySync(String path) =>
       (_getTypeSync(path, true) == FileSystemEntityType.DIRECTORY._type);
 
 
   static _throwIfError(Object result, String msg) {
     if (result is OSError) {
-      throw new FileIOException(msg, result);
+      throw new FileException(msg, result);
     } else if (result is ArgumentError) {
       throw result;
     }
   }
 }