[gnome-shell] layout: Only emit fullscreen-changed if things actually changed

[Jasper St. Pierre <jstpierre src gnome org>]

commit 6c0f48ce25d0c275928ef2d476cc09c33505ffea
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Fri Mar 15 14:54:22 2013 -0400

    layout: Only emit fullscreen-changed if things actually changed
    
    This prevents the message tray from doing a lot of work that
    it doesn't need to.

 js/ui/layout.js |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/layout.js b/js/ui/layout.js
index 1fff9cc..32b65e6 100644
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -1066,7 +1066,8 @@ const LayoutManager = new Lang.Class({
             }
         }
 
-        this.emit('fullscreen-changed');
+        if (changed)
+            this.emit('fullscreen-changed');
     },
 
     _updateRegions: function() {