Part of the decoupling of Window from OutputDevice. We now get
the Window's OutputDevice instance and manipulate this. Do not rely
on the inherited function.

Conflicts:
	vcl/source/window/window.cxx
	vcl/source/window/window2.cxx

Change-Id: I5e5241ed9eb586bc31ae9411cd7eef460aa707c3
Reviewed-on: https://gerrit.libreoffice.org/7800Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>