Merge pull request #13337 from MoonE/fix-rendering-test

Fix error when accessing ready property of renderer

test/rendering/cases/stacking/main.js

@@ -28,6 +28,10 @@ class Element extends Layer {
   render() {
     return this.element;
   }
+
+  createRenderer() {
+    return {};
+  }
 }
 
 // elements for stacked controls