Fix checked mode error and update status file

runtime/lib/uri_patch.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.
 
 // VM implementation of Uri.
 typedef Uri _UriBaseClosure();
 
-void _unsupportedUriBase() {
+Uri _unsupportedUriBase() {
   throw new UnsupportedError("'Uri.base' is not supported");
 }
 
 // _uriBaseClosure can be overwritten by the embedder to supply a different
 // value for Uri.base.
 _UriBaseClosure _uriBaseClosure = _unsupportedUriBase;
 
 patch class Uri {
   static final bool _isWindowsCached = _isWindowsPlatform;
 
   /* patch */ static bool get _isWindows => _isWindowsCached;
 
   /* patch */ static Uri get base => _uriBaseClosure();
 
   static bool get _isWindowsPlatform native "Uri_isWindowsPlatform";
 }