Rephrase some comments.

runtime/bin/directory.dart

 // Copyright (c) 2011, 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.
 
 interface Directory factory _Directory {
   /**
    * Creates a directory object. The path is either a full path or
    * relative to the directory in which the Dart VM was
    * started.
    */
@@ skipping 27 matching lines @@
   void list([bool recursive]);
 
   /**
    * Sets the directory handler that is called for all directories
    * during listing operations. The directory handler is called with
    * the full path of the directory.
    */
   void set dirHandler(void dirHandler(String dir));
 
   /**
-   * Sets the file handler that is called for all files during listing
+   * Sets the handler that is called for all files during listing
    * operations. The file handler is called with the full path of the
    * file.
    */
   void set fileHandler(void fileHandler(String file));
 
   /**
-   * Set the done handler that is called when a directory listing is
+   * Set the handler that is called when a directory listing is
    * done. The handler is called with an indication of whether or not
    * the listing operation completed.
    */

[Bill Hesse, 2011/11/08 09:35:39]

Maybe we can leave the argument as a bool, if we also declare
static final bool COMPLETED = true;
static final bool DID_NOT_COMPLETE = false;

Otherwise, I think bool arguments are bad.  But that should be a different
changelist.

   void set doneHandler(void doneHandler(bool completed));
 
   /**
-   * Sets the error handler that is called on error listing
-   * directories.
+   * Sets the handler that is called on error listing directories.
    */
   void set errorHandler(void errorHandler(String error));
 
   /**
    * Gets the path of this directory.
    */
   final String path;
 }
 
 
 class DirectoryException {
   const DirectoryException(String this.message);
   String toString() => "DirectoryException: $message";
   final String message;
 }