Set Height limit to frame.

layouts/scripts/frame/editor.js

@@ -8,7 +8,11 @@ export function setupFrameResizeListener() {
     }
 
     const data = JSON.parse(e.data.substring(RESIZE_CODE.length))
-    previewFrame.style.height = data.height + 'px'
+    let height = Number.parseInt(data.height)
+    if (height > 20000) {
+      height = 20000; // Limit max height.
+    }
+    previewFrame.style.height = height + 'px'
   });
 }