anchor.diff:  import 'package:chrome/chrome_app.dart' as chrome;
   
   import "dnd.dart";
  -
  -TextAreaElement textarea = null;
  -ButtonElement saveFileButton = null;
   
   void errorHandler(message) {
     window.console.error(message);
  
positive.code:     }
    }
    else {
      textarea.innerHtml = "";
      file_path.value = entry.fullPath;
      file_size.text = "N/A";
  
negative.code:   }
    else if (entry.isFile) {
      output.value = "";
      readAsText(entry).then((result) {
        TextAreaElement textarea = document.querySelector("textarea");
        textarea.innerHtml = result;
      });
      ButtonElement saveFileButton = document.querySelector("#save_file");
      saveFileButton.disabled = false;
    }
  }
  
  void main() {
    var dnd = new DnDFileController("body", onDrop);
  }