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.

diff --git a/js/ui/layout.js b/js/ui/layout.js
index 1fff9cc536f4cc136b10c335159f9adfac2c022a..32b65e603be93306314490004d8d2c497e32ffdd 100644 (file)
--- 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() {