This signal is emitted when an error occurs during the download
operation. The given @error, of the domain %WEBKIT_DOWNLOAD_ERROR,
contains further details of the failure. If the download is cancelled
with webkit_download_cancel(), this signal is emitted with error
%WEBKIT_DOWNLOAD_ERROR_CANCELLED_BY_USER. The download operation finishes
after an error and #WebKitDownload::finished signal is emitted after this one.
This signal is emitted when an error occurs during the download operation. The given @error, of the domain %WEBKIT_DOWNLOAD_ERROR, contains further details of the failure. If the download is cancelled with webkit_download_cancel(), this signal is emitted with error %WEBKIT_DOWNLOAD_ERROR_CANCELLED_BY_USER. The download operation finishes after an error and #WebKitDownload::finished signal is emitted after this one.