Issue 3562. Analyzer should not warn about shadowing

samples/ui_lib/util/Uri.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.
 
 /**
  * A parsed URI, inspired by:
  * http://closure-library.googlecode.com/svn/docs/class_goog_Uri.html
  */
 class Uri extends uri.Uri {
   /**
@@ skipping 55 matching lines @@
     if (component == null) return component;
 
     return component.replaceAll('%3A', ':')
                     .replaceAll('%2F', '/')
                     .replaceAll('%3F', '?')
                     .replaceAll('%3D', '=')
                     .replaceAll('%26', '&')
                     .replaceAll('%20', ' ');
   }
 
-  Uri.fromString(String uri) : super.fromString(uri);
+  Uri.fromString(String uriString) : super.fromString(uriString);
 }