Replace macro with constexpr now that we require C++14.

Change-Id: I71531f4cb3b306687c0d532d5e5e9c1c36ed5357
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/406476
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed