tdf#154982 vcl: PDF Export: split BeginStructureElement

... into 3 parts:
EnsureStructureElement/InitStructureElement/BeginStructureElement

So EnsureStructureElement and BeginStructureElement/EndStructureElement
can be called multiple times for the same object, passing in a unique
key and PDFExtOutDevData will only create the element once.

InitStructureElement will be used exactly once for each object when its
actual content is exported.

In PDFExtOutDevData rely on the indexes being the same here and in
PDFWriterImpl, because then only PDFExtOutDevData needs to maintain the
map from key to index.

Change-Id: Idea6e34627fe559038cf13cf01dafe84b759e3c8
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/154357
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

0 files changed, 0 insertions, 0 deletions