Keep in sync with the current tree.
The changes are mostly caused by updates in the internal hierarchy of
composite widgets, and the fact that the order in which the widget tree
is traversed is not exactly stable.
This value is highly sensitive to changes in the theme; we
don't want to have to tweak hardcoded integers in this test case
every time we rev gnome-themes-standard.
Future iterations could do more heuristic matching, but this
is enough for now.
https://bugzilla.gnome.org/show_bug.cgi?id=704747