Update comment why it's important to destroy textures after submit, n…

…ot before

crates/egui-wgpu/src/winit.rs

@@ -684,6 +684,9 @@ impl Painter {
             vsync_sec += start.elapsed().as_secs_f32();
         };
 
+        // Free textures marked for destruction **after** queue submit since they might still be used in the current frame.
+        // Calling `wgpu::Texture::destroy` on a texture that is still in use would invalidate the command buffer(s) it is used in.
+        // However, once we called `wgpu::Queue::submit`, it is up for wgpu to determine how long the underlying gpu resource has to live.
         {
             let mut renderer = render_state.renderer.write();
             for id in &textures_delta.free {