Fixed DSLParser bit rot

DSLParser had been broken by https://skia-review.googlesource.com/c/skia/+/436156,
but it was not caught due to being #ifdef'ed out. This restores it to working
order.

Change-Id: Ic30ed6bc1950aeed08f7ae32f8060ec29cdc3cd9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437019
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
5 files changed