Revert "scene: try to import buffers as textures before rendering"

This reverts commit 3db1bcbe64.

Since [1], importing buffers as textures before wlr_renderer_begin isn't
necessary anymore.

[1]: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/3464

include/wlr/types/wlr_scene.h

@@ -69,9 +69,6 @@ struct wlr_scene {
 	// May be NULL
 	struct wlr_presentation *presentation;
 	struct wl_listener presentation_destroy;
-
-	// List of buffers which need to be imported as textures
-	struct wl_list pending_buffers; // wlr_scene_buffer.pending_link
 };
 
 /** A sub-tree in the scene-graph. */
@@ -118,7 +115,6 @@ struct wlr_scene_buffer {
 	struct wlr_fbox src_box;
 	int dst_width, dst_height;
 	enum wl_output_transform transform;
-	struct wl_list pending_link; // wlr_scene.pending_buffers
 };
 
 /** A viewport for an output in the scene-graph */

types/scene/wlr_scene.c

@@ -130,7 +130,6 @@ void wlr_scene_node_destroy(struct wlr_scene_node *node) {
 		break;
 	case WLR_SCENE_NODE_BUFFER:;
 		struct wlr_scene_buffer *scene_buffer = scene_buffer_from_node(node);
-		wl_list_remove(&scene_buffer->pending_link);
 		wlr_texture_destroy(scene_buffer->texture);
 		wlr_buffer_unlock(scene_buffer->buffer);
 		free(scene_buffer);
@@ -146,7 +145,6 @@ struct wlr_scene *wlr_scene_create(void) {
 	scene_node_init(&scene->node, WLR_SCENE_NODE_ROOT, NULL);
 	wl_list_init(&scene->outputs);
 	wl_list_init(&scene->presentation_destroy.link);
-	wl_list_init(&scene->pending_buffers);
 	return scene;
 }
 
@@ -362,9 +360,6 @@ struct wlr_scene_buffer *wlr_scene_buffer_create(struct wlr_scene_node *parent,
 
 	scene_node_damage_whole(&scene_buffer->node);
 
-	struct wlr_scene *scene = scene_node_get_root(parent);
-	wl_list_insert(&scene->pending_buffers, &scene_buffer->pending_link);
-
 	return scene_buffer;
 }
 
@@ -1118,15 +1113,6 @@ bool wlr_scene_output_commit(struct wlr_scene_output *scene_output) {
 		return true;
 	}
 
-	// Try to import new buffers as textures
-	struct wlr_scene_buffer *scene_buffer, *scene_buffer_tmp;
-	wl_list_for_each_safe(scene_buffer, scene_buffer_tmp,
-			&scene_output->scene->pending_buffers, pending_link) {
-		scene_buffer_get_texture(scene_buffer, renderer);
-		wl_list_remove(&scene_buffer->pending_link);
-		wl_list_init(&scene_buffer->pending_link);
-	}
-
 	wlr_renderer_begin(renderer, output->width, output->height);
 
 	int nrects;