Update SkSLTest to use SkEnumBitMask.

This enforces correct usage of flag bits.

Change-Id: Ia153e6c5c8c084e8386d587c890ab0f689cefcac
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/696856
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2 files changed