At least with the randomised test, it can happen that deleting one
redline will recursively delete other redlines that are located in
the hidden content section of the redline, or at least try to and
crash because those have already been deleted before.

The callers will either delete 1 redline, or delete all of them
via DeleteAndDestroyAll(), so put a safer loop into
DeleteAndDestroyAll() and have DeleteAndDestroy() only delete 1.

Change-Id: I9c4225544a43a4a03f4eb7b6f56e7fe848c8ca54