Code cleanup (mostly io lib and some http lib).

sdk/lib/io/directory_impl.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.
 
 part of dart.io;
 
 class _Directory extends FileSystemEntity implements Directory {
   final String path;
 
-  _Directory(String this.path) {
+  _Directory(this.path) {
     if (path is! String) {
       throw new ArgumentError('${Error.safeToString(path)} '
                               'is not a String');
     }
   }
 
   external static _current();
   external static _setCurrent(path);
   external static _createTemp(String path);
   external static String _systemTemp();
@@ skipping 202 matching lines @@
       throw new ArgumentError();
     }
     return _list(
         FileSystemEntity._trimTrailingPathSeparators(path),
         recursive,
         followLinks);
   }
 
   String toString() => "Directory: '$path'";
 
-  bool _isErrorResponse(response) {
-    return response is List && response[0] != _SUCCESS_RESPONSE;
-  }
+  bool _isErrorResponse(response) =>
+      response is List && response[0] != _SUCCESS_RESPONSE;
 
   _exceptionOrErrorFromResponse(response, String message) {
     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 FileSystemException(message, path, err);
@@ skipping 19 matching lines @@
   final bool recursive;
   final bool followLinks;
 
   StreamController controller;
   int id;
   bool canceled = false;
   bool nextRunning = false;
   bool closed = false;
   Completer closeCompleter = new Completer();
 
-  _AsyncDirectoryLister(String this.path,
-                        bool this.recursive,
-                        bool this.followLinks) {
+  _AsyncDirectoryLister(this.path, this.recursive, this.followLinks) {
     controller = new StreamController(onListen: onListen,
                                       onResume: onResume,
                                       onCancel: onCancel,
                                       sync: true);
   }
 
   Stream get stream => controller.stream;
 
   void onListen() {
     _IOService.dispatch(_DIRECTORY_LIST_START, [path, recursive, followLinks])
@@ skipping 92 matching lines @@
       controller.addError(
           new FileSystemException("Directory listing failed",
                                  errorPath,
                                  err));
     } else {
       controller.addError(
           new FileSystemException("Internal error"));
     }
   }
 }