Remove DirectoryException and LinkException from dart:io and use FileException instaed.

sdk/lib/io/link.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;
 
 /**
  * [Link] objects are references to filesystem links.
  *
  */
@@ skipping 88 matching lines @@
   Link get absolute;
 
   /**
    * Gets the target of the link. Returns a future that completes with
    * the path to the target.
    *
    * If the returned target is a relative path, it is relative to the
    * directory containing the link.
    *
    * If the link does not exist, or is not a link, the future completes with
-   * a LinkException.
+   * a FileSystemException.
    */
   Future<String> target();
 
   /**
    * Synchronously gets the target of the link. Returns the path to the target.
    *
    * If the returned target is a relative path, it is relative to the
    * directory containing the link.
    *
-   * If the link does not exist, or is not a link, throws a LinkException.
+   * If the link does not exist, or is not a link, throws a FileSystemException.
    */
   String targetSync();
 }
 
 
 class _Link extends FileSystemEntity implements Link {
   final String path;
 
   _Link(String this.path) {
     if (path is! String) {
@@ skipping 39 matching lines @@
 
   // Put target into the form "\??\C:\my\target\dir".
   String _makeWindowsLinkTarget(String target) {
     Uri base = new Uri.file('${Directory.current.path}\\');
     Uri link = new Uri.file(path);
     Uri destination = new Uri.file(target);
     String result = base.resolveUri(link).resolveUri(destination).toFilePath();
     if (result.length > 3 && result[1] == ':' && result[2] == '\\') {
       return '\\??\\$result';
     } else {
-      throw new LinkException(
+      throw new FileSystemException(
           'Target $result of Link.create on Windows cannot be converted' +
           ' to start with a drive letter.  Unexpected error.');
     }
   }
 
   void updateSync(String target) {
     // TODO(12414): Replace with atomic update, where supported by platform.
     // Atomically changing a link can be done by creating the new link, with
     // a different name, and using the rename() posix call to move it to
     // the old name atomically.
@@ skipping 57 matching lines @@
   }
 
   String targetSync() {
     var result = _File._linkTarget(path);
     throwIfError(result, "Cannot read link", path);
     return result;
   }
 
   static throwIfError(Object result, String msg, [String path = ""]) {
     if (result is OSError) {
-      throw new LinkException(msg, path, result);
+      throw new FileSystemException(msg, path, result);
     }
   }
 
   bool _isErrorResponse(response) {
     return response is List && response[0] != _SUCCESS_RESPONSE;
   }
 
   _exceptionFromResponse(response, String message, String path) {
     assert(_isErrorResponse(response));
     switch (response[_ERROR_RESPONSE_ERROR_TYPE]) {
       case _ILLEGAL_ARGUMENT_RESPONSE:
         return new ArgumentError();
       case _OSERROR_RESPONSE:
         var err = new OSError(response[_OSERROR_RESPONSE_MESSAGE],
                               response[_OSERROR_RESPONSE_ERROR_CODE]);
-        return new LinkException(message, path, err);
+        return new FileSystemException(message, path, err);
       default:
         return new Exception("Unknown error");
     }
   }
 }
-
-
-class LinkException implements IOException {
-  const LinkException([String this.message = "",
-                       String this.path = "",
-                       OSError this.osError = null]);
-  String toString() {
-    StringBuffer sb = new StringBuffer();
-    sb.write("LinkException");
-    if (!message.isEmpty) {
-      sb.write(": $message");
-      if (path != null) {
-        sb.write(", path = $path");
-      }
-      if (osError != null) {
-        sb.write(" ($osError)");
-      }
-    } else if (osError != null) {
-      sb.write(": $osError");
-      if (path != null) {
-        sb.write(", path = $path");
-      }
-    }
-    return sb.toString();
-  }
-  final String message;
-  final String path;
-  final OSError osError;
-}