// Always schedule files to be deleted at the end of the private browsing
      // mode, regardless of the value of the pref.
      if (this.source.isPrivate) {
        gExternalAppLauncher.deleteTemporaryPrivateFileWhenPossible(
          new FileUtils.File(this.target.path)
        );
      } else if (
        Services.prefs.getBoolPref("browser.helperApps.deleteTempFileOnExit") &&
        Services.prefs.getBoolPref(
          "browser.download.start_downloads_in_tmp_dir",
          false
        )
      ) {
        gExternalAppLauncher.deleteTemporaryFileOnExit(
          new FileUtils.File(this.target.path)
        );
      }

// The file with the partially downloaded data has restrictive permissions
    // that don't allow other users on the system to access it.  Now that the
    // download is completed, we need to adjust permissions based on whether
    // this is a permanently downloaded file or a temporary download to be
    // opened read-only with an external application.
    try {
      // The following logic to determine whether this is a temporary download
      // is due to the fact that "deleteTempFileOnExit" is false on Mac, where
      // downloads to be opened with external applications are preserved in
      // the "Downloads" folder like normal downloads.
      let isTemporaryDownload =
        aDownload.launchWhenSucceeded &&
        (aDownload.source.isPrivate ||
          (Services.prefs.getBoolPref(
            "browser.helperApps.deleteTempFileOnExit"
          ) &&
            !Services.prefs.getBoolPref(
              "browser.download.improvements_to_download_panel"
            )));