This required several fixes to make viewer able to display Linux's XUL
filepicker correctly, including making modal dialogs work, delaying the
showing of chrome windows until the document has fully loaded, and fixing
the problem on gtk where space was reserved for a menubar even if the
window doesn't have one.
r=jag, sr=shaver.
git-svn-id: svn://10.0.0.236/trunk@101003 18797224-902f-48f8-a5cc-f745e15eee43