Consistently use setters to set event handlers in native APIs.

runtime/bin/directory_impl.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.
 
 
 class _DirectoryListingIsolate extends Isolate {
 
   _DirectoryListingIsolate() : super.heavy();
 
   void main() {
@@ skipping 15 matching lines @@
              SendPort filePort,
              SendPort donePort,
              SendPort errorPort) native "Directory_List";
 }
 
 
 class _Directory implements Directory {
 
   _Directory(String this._path);
 
-  bool exists() {
+  bool existsSync() {
     int exists = _exists(_path);
     if (exists < 0) {
       // TODO(ager): Supply a better error message.
       throw new DirectoryException("Diretory exists test failed: $_path");
     }
     return (exists == 1);
   }
 
-  void create() {
+  void createSync() {
     if (!_create(_path)) {
       // TODO(ager): Supply a better error message.
       throw new DirectoryException("Directory creation failed: $_path");
     }
   }
 
-  void delete() {
+  void deleteSync() {
     if (!_delete(_path)) {
       // TODO(ager): Supply a better error message.
       throw new DirectoryException("Directory deletion failed: $_path");
     }
   }
 
   void list([bool recursive = false]) {
     new _DirectoryListingIsolate().spawn().then((port) {
       // Build a map of parameters to the directory listing isolate.
       Map listingParameters = new Map();
@@ skipping 50 matching lines @@
         _closePort(dirPort);
         _closePort(filePort);
         _closePort(closePortsPort);
       });
 
       // Send the listing parameters to the isolate.
       port.send(listingParameters, closePortsPort.toSendPort());
     });
   }
 
-  void setDirHandler(void dirHandler(String dir)) {
+  void set dirHandler(void dirHandler(String dir)) {
     _dirHandler = dirHandler;
   }
 
-  void setFileHandler(void fileHandler(String file)) {
+  void set fileHandler(void fileHandler(String file)) {
     _fileHandler = fileHandler;
   }
 
-  void setDoneHandler(void doneHandler(bool completed)) {
+  void set doneHandler(void doneHandler(bool completed)) {
     _doneHandler = doneHandler;
   }
 
-  void setErrorHandler(void errorHandler(String error)) {
+  void set errorHandler(void errorHandler(String error)) {
     _errorHandler = errorHandler;
   }
 
   void _closePort(ReceivePort port) {
     if (port !== null) {
       port.close();
     }
   }
 
   String get path() { return _path; }
 
   int _exists(String path) native "Directory_Exists";
   bool _create(String path) native "Directory_Create";
   bool _delete(String path) native "Directory_Delete";
 
   var _dirHandler;
   var _fileHandler;
   var _doneHandler;
   var _errorHandler;
 
   String _path;
 }