This signal is emitted when the user interacts with a HTML element, requesting from WebKit to show
a dialog to select one or more files to be uploaded. To let the
application know the details of the file chooser, as well as to
allow the client application to either cancel the request or
perform an actual selection of files, the signal will pass an
instance of the
WebKitFileChooserRequest in the
The default signal handler will asynchronously run a regular
GtkFileChooserDialog for the user to interact with.
The default handler is called after the handlers added via
The data is owned by the caller of the function.