Don't execute OpsTask which will have no effect on their target.

Change-Id: Ia58555e7387ef0f80893a58150b3f76d77c26d6e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/244896
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
2 files changed