private void on_download_updated(cef_download_handler_t *self, cef_browser_t *browser, cef_download_item_t *download_item, cef_download_item_callback_t *callback)
        {
            CheckSelf(self);

            var m_browser       = CefBrowser.FromNative(browser);
            var m_download_item = CefDownloadItem.FromNative(download_item);
            var m_callback      = CefDownloadItemCallback.FromNative(callback);

            OnDownloadUpdated(m_browser, m_download_item, m_callback);

            m_download_item.Dispose();
        }
 /// <summary>
 /// Called when a download's status or progress information has been updated.
 /// This may be called multiple times before and after OnBeforeDownload().
 /// Execute |callback| either asynchronously or in this method to cancel the
 /// download if desired. Do not keep a reference to |download_item| outside of
 /// this method.
 /// </summary>
 protected virtual void OnDownloadUpdated(CefBrowser browser, CefDownloadItem downloadItem, CefDownloadItemCallback callback)
 {
 }