So a view can be aware where the graphic selections of other views are.

Change-Id: I0cc420cfe4bf3824fbfa1a58da889cac5e9a7b60
Reviewed-on: https://gerrit.libreoffice.org/26863Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>