popup: call ensure style on the children
popup: call ensure style on the children

The popup is frequently not mapped, but other widgets may want to know it's
size. If style is not ensured on the children, then the size information
may be wrong.

Fixes: http://bugzilla.moblin.org/show_bug.cgi?id=9998

pwithnall/mx,jonnylamb/mx,pwithnall/mx,clutter-project/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,jonnylamb/mx,clutter-project/mx,clutter-project/mx