and is the branch checkin for bug 31713.
The problem is the code cheked into 3.258 does it for all windows, when you really
only want to do it for top level windows.
r=kmcclusk b=31713
git-svn-id: svn://10.0.0.236/trunk@62925 18797224-902f-48f8-a5cc-f745e15eee43