MAGETWO-53223: [Github] Magento performance decreases significantly if Merge CSS Files = Yes #4710

Author: shiftedreality

lib/internal/Magento/Framework/View/Asset/Merged.php

@@ -37,7 +37,7 @@ class Merged implements \Iterator
     /**
      * @var Filesystem
      */
-    protected $filesystem;
+    private $filesystem;
 
     /**
      * @var MergeableInterface[]
@@ -195,6 +195,7 @@ public static function getRelativeDir()
 
     /**
      * @return Filesystem
+     * @deprecated
      */
     private function getFilesystem()
     {