Fix StencilResolveProcessor to declare its outputs.

This crossed in the mail with http://review.skia.org/382476

Change-Id: I09ca2ff20bb2dc0846b591893d06823577faea29
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/382758
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
1 file changed