Update charted to 0.4.8 and roll

packages/watcher/lib/src/file_watcher/polling.dart

 // Copyright (c) 2015, 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.
 
-library watcher.file_watcher.polling;
-
 import 'dart:async';
 import 'dart:io';
 
 import '../file_watcher.dart';
 import '../resubscribable.dart';
 import '../stat.dart';
 import '../watch_event.dart';
 
 /// Periodically polls a file for changes.
 class PollingFileWatcher extends ResubscribableWatcher implements FileWatcher {
@@ skipping 67 matching lines @@
       _lastModified = modified;
       _eventsController.add(new WatchEvent(ChangeType.MODIFY, path));
     }
   }
 
   void close() {
     _timer.cancel();
     _eventsController.close();
   }
 }