PaintToDevice() method was designed for pixel based windows,
now I added some scaling to handle different units.

Change-Id: Id242c44101c1e842409ba3a9b13291e48bdd44ca
Reviewed-on: https://gerrit.libreoffice.org/49543Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>
(cherry picked from commit d6a2dc03)