Convert device space effect back to subclass.

No functional change.

This will allow it to use a different sample usage in the future.

Bug: skia:12198
Change-Id: I6d8bef383bf8a75f06e4cd8aa1c5a48188b53592
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/433677
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2 files changed