gui: fix dirty

dist/preview release/gui/babylon.gui.js

@@ -839,6 +839,7 @@ var BABYLON;
             };
             Control.prototype._markMatrixAsDirty = function () {
                 this._isMatrixDirty = true;
+                this._markAsDirty();
             };
             Control.prototype._markAsDirty = function () {
                 this._isDirty = true;

gui/src/controls/control.ts

@@ -374,6 +374,7 @@ module BABYLON.GUI {
 
         public _markMatrixAsDirty(): void {
             this._isMatrixDirty = true;
+            this._markAsDirty();
         }
 
         protected _markAsDirty(): void {