Implementation class for {@link FileUpload}.

class FileUploadImpl {

 /**
  * Create instance of DomHelper depends on broswer.
  */
 factory FileUploadImpl.browserDependent() {
   return new FileUploadImpl._internal();
 }

 FileUploadImpl._internal();

 /**
  * Initialize the impl class.
  *
  * @param fileUpload the {@link FileUpload} to handle
  */
 void init(FileUpload fileUpload) {}

 /**
  * Handle the browser event.
  *
  * @param event the native event
  * @return true to fire the event normally, false to ignore it
  */
 bool onBrowserEvent(dart_html.Event event) {
   return true;
 }
}