anchor.diff:  
     Future setContents(String contents) {
       return _fileEntry.writeText(contents).then((_) {
  -      workspace._fireEvent(new ResourceChangeEvent(this, ResourceEventType.CHANGE));
  +      workspace._fireEvent(new ResourceChangeEvent(this,
  +          ResourceEventType.CHANGE));
       });
     }
   
  
positive.code: 
  import 'dart:async';
  import 'dart:convert' show JSON;
  import 'dart:html' as html;
  
  import 'package:chrome_gen/chrome_app.dart' as chrome;
  import 'package:logging/logging.dart';
  
negative.code:   Future setBytes(List<int> data) {
      chrome.ArrayBuffer bytes = new chrome.ArrayBuffer.fromBytes(data);
      return _fileEntry.writeBytes(bytes).then((_) {
        workspace._fireEvent(new ResourceChangeEvent(this,
            ResourceEventType.CHANGE));
      });
    }
  
  