I have to use the other way to specify an a11y role, both are implemented in
the vcl parser, but in my gtk3-3.24.7 the role tag crashes the gtk parser,
while the other route works fine.

The CONTENT_FLOWS_TO accessibility relation is another additional complexity
over the norm

Change-Id: Ia096bcbe9f00f9944e4e4d5ad9bb1a52d19c7b3f
Reviewed-on: https://gerrit.libreoffice.org/69569
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>