use PathSubRun for Slugs

Change-Id: I7b1ae94f8abdaf84d9dc47ee7ecdb6044b694da8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/502304
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed