Store rendererd source on the layer instead of the layer state

test/rendering/cases/webgl-invisible-group/main.js

@@ -0,0 +1,27 @@
+import Group from '../../../../src/ol/layer/Group.js';
+import Map from '../../../../src/ol/Map.js';
+import OSM from '../../../../src/ol/source/OSM.js';
+import TileLayer from '../../../../src/ol/layer/WebGLTile.js';
+import View from '../../../../src/ol/View.js';
+
+new Map({
+  layers: [
+    new Group({
+      visible: false,
+      layers: [
+        new TileLayer({
+          source: new OSM(),
+        }),
+      ],
+    }),
+  ],
+  target: 'map',
+  view: new View({
+    center: [0, 0],
+    zoom: 0,
+  }),
+});
+
+render({
+  message: 'webgl tile layer in an invisible group is not rendered',
+});