Label constants with k prefix (not g) and use constexpr.

Correct prefixes are important for readability. The `g` prefix briefly
led me to believe that our random number generation had static state.

Change-Id: I9187f1da1283e1a42f250ba0c3502807d7b711a7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/308918
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>
1 file changed