[gnome-shell] Fix expand animation for submenus

[Owen Taylor <otaylor src gnome org>]

commit 82e2ab89c517b2d9b270d598f8ebf5245a22cf18
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Thu Mar 31 15:51:38 2011 -0400

    Fix expand animation for submenus
    
    Figuring out the size of an unmapped actor is not completely
    reliable because styles aren't fully assigned until an actor
    is mapped. So show the submenu before computing the size we
    want to tween to.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=645949

 js/ui/popupMenu.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/popupMenu.js b/js/ui/popupMenu.js
index 99e7a33..1f31c18 100644
--- a/js/ui/popupMenu.js
+++ b/js/ui/popupMenu.js
@@ -1059,9 +1059,9 @@ PopupSubMenu.prototype = {
         // we don't implement the !animate case because that doesn't
         // currently get used...
 
+        this.actor.show();
         let [naturalHeight, minHeight] = this.actor.get_preferred_height(-1);
         this.actor.height = 0;
-        this.actor.show();
         this.actor._arrow_rotation = this._arrow.rotation_angle_z;
         Tweener.addTween(this.actor,
                          { _arrow_rotation: 90,