Window: Apply display:none after initialize, not before

While it appeared to already do it after (or rather, at the end
of the initialize method), subclasses call the parent method
first. So aside from the little Window#initialize was doing itself,
the majority was happening afterwards which is probematic due to
style computations no longer being accurate.

Bug: 65373
Change-Id: I9aa398d56ded6b58fc23a8c2139d9610e09f4a52