Use scene-graph for damage tracking

References: https://github.com/swaywm/wlroots/pull/3117

cage.c

@@ -187,9 +187,6 @@ usage(FILE *file, const char *cage)
 		"Usage: %s [OPTIONS] [--] APPLICATION\n"
 		"\n"
 		" -d\t Don't draw client side decorations, when possible\n"
-#ifdef DEBUG
-		" -D\t Turn on damage tracking debugging\n"
-#endif
 		" -h\t Display this help message\n"
 		" -m extend Extend the display across all connected outputs (default)\n"
 		" -m last Use only the last connected output\n"
@@ -205,20 +202,11 @@ static bool
 parse_args(struct cg_server *server, int argc, char *argv[])
 {
 	int c;
-#ifdef DEBUG
-	while ((c = getopt(argc, argv, "dDhm:rsv")) != -1) {
-#else
 	while ((c = getopt(argc, argv, "dhm:rsv")) != -1) {
-#endif
 		switch (c) {
 		case 'd':
 			server->xdg_decoration = true;
 			break;
-#ifdef DEBUG
-		case 'D':
-			server->debug_damage_tracking = true;
-			break;
-#endif
 		case 'h':
 			usage(stdout, argv[0]);
 			return false;