Clear special surfaces with red color on debug tests

This was intended to be enabled when testing on the CI or CQ, however
the SK_IS_BOT define has not been set for over 3 years.

Change-Id: I5e0748bae5b8d59d959c715aedefa701d6247e7c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/626659
Reviewed-by: Robert Phillips <robertphillips@google.com>
Auto-Submit: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed