I suppose it is the same misconception as in fdo#55931 - I am convinced that
the font metrics should not be used here.

Looks to me as if in the past, the font width computation was broken somewhere
deep inside OOo, and everyone instead of fixing the root cause was just
working that around by using the FontMetric; and then one day the root cause
was fixed, and all the workarounds broke ;-) - but that is just a theory.

Change-Id: I741bf8f4eaea4f7d8bc698dc9a8124109dfb8c20