Fix panic in surface cleanup

wgpu-core/src/hub.rs

@@ -724,6 +724,14 @@ impl<A: HalApi, F: GlobalIdentityHandlerFactory> Hub<A, F> {
 
         for element in surface_guard.map.iter_mut() {
             if let Element::Occupied(ref mut surface, _epoch) = *element {
+                if surface
+                    .presentation
+                    .as_ref()
+                    .map_or(wgt::Backend::Empty, |p| p.backend())
+                    != A::VARIANT
+                {
+                    continue;
+                }
                 if let Some(present) = surface.presentation.take() {
                     let device = &devices[present.device_id.value];
                     let suf = A::get_surface_mut(surface);

wgpu-core/src/present.rs

@@ -36,6 +36,12 @@ pub(crate) struct Presentation {
     pub(crate) acquired_texture: Option<Stored<TextureId>>,
 }
 
+impl Presentation {
+    pub(crate) fn backend(&self) -> wgt::Backend {
+        crate::id::TypedId::unzip(self.device_id.value.0).2
+    }
+}
+
 #[derive(Clone, Debug, Error)]
 pub enum SurfaceError {
     #[error("surface is invalid")]