It saves lots of extra code: no separately checking if a line exists,
and then getting the width.  Closely matches the existing CalcLineSpace.

sc/source/ui/view/printfun.cxx is another place that could use this
heavily to replace their lcl_LineTotal function. Perhaps something
good for an easyHack. (Wait until LO5.4, since much of the logic
should use CalcLineSpace(,true) instead, and that function probably
will have the default bEvenIfNoLine changed to true. Compiler doesn't
like providing "true" when the default value is also "true".)

Change-Id: I298d057b2bf04959434736f6ab2666d2de4222f9
Reviewed-on: https://gerrit.libreoffice.org/30589Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Justin Luth <justin_luth@sil.org>