Revert "Fix remaining strong-mode warnings and errors in dart:io."

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 205 matching lines @@
     // the old name atomically.
     deleteSync();
     createSync(target);
   }
 
   Future<Link> update(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.
-    return delete().then/*<Link>*/((_) => create(target));
+    return delete().then((_) => create(target));
   }
 
   Future<Link> _delete({bool recursive: false}) {
     if (recursive) {
       return new Directory(path).delete(recursive: true).then((_) => this);
     }
     return _IOService._dispatch(_FILE_DELETE_LINK, [path]).then((response) {
       if (_isErrorResponse(response)) {
         throw _exceptionFromResponse(response, "Cannot delete link", path);
       }
@@ skipping 59 matching lines @@
         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);
       default:
         return new Exception("Unknown error");
     }
   }
 }