output: remove wlr_output_impl.export_dmabuf

No backend is using it anymore.

include/wlr/interfaces/wlr_output.h

@@ -83,11 +83,6 @@ struct wlr_output_impl {
 	 * Zero can be returned if the output doesn't support gamma LUTs.
 	 */
 	size_t (*get_gamma_size)(struct wlr_output *output);
-	/**
-	 * Export the output's current back-buffer as a DMA-BUF.
-	 */
-	bool (*export_dmabuf)(struct wlr_output *output,
-		struct wlr_dmabuf_attributes *attribs);
 	/**
 	 * Get the list of formats suitable for the cursor, assuming a buffer with
 	 * the specified capabilities.

types/wlr_export_dmabuf_v1.c

@@ -135,7 +135,7 @@ static void manager_handle_capture_output(struct wl_client *client,
 
 	wl_list_insert(&manager->frames, &frame->link);
 
-	if (output == NULL || !output->enabled || !output->impl->export_dmabuf) {
+	if (output == NULL || !output->enabled) {
 		zwlr_export_dmabuf_frame_v1_send_cancel(frame->resource,
 			ZWLR_EXPORT_DMABUF_FRAME_V1_CANCEL_REASON_PERMANENT);
 		frame_destroy(frame);

types/wlr_output.c

@@ -926,10 +926,6 @@ size_t wlr_output_get_gamma_size(struct wlr_output *output) {
 
 bool wlr_output_export_dmabuf(struct wlr_output *output,
 		struct wlr_dmabuf_attributes *attribs) {
-	if (output->impl->export_dmabuf) {
-		return output->impl->export_dmabuf(output, attribs);
-	}
-
 	if (output->front_buffer == NULL) {
 		return false;
 	}