The geometry is used for mouse hit tests for mapping
LO mouse events to popup positions.
This way (popup) menus become at at least usable.

Change-Id: Ic2b409d7a8937320c70b9f377374fe7d51e4ebf3
Reviewed-on: https://gerrit.libreoffice.org/47276Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>