tree b080c249e6aaa3f32f8ed280eeb321f1a2a688a2
parent 75c5168b41c312f5df009cf004f04c1aada1d859
author John Stiles <johnstiles@google.com> 1595252751 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1595262178 +0000

Factor out random fragment-processor generation into a helper class.

The helper class allows us to regenerate a "random" fragment processor
with the same seed as many times as desired. This lets us check the
`compatibleWithCoverageAsAlpha` optimization without needing to clone
the input FP; instead, we can actually generate the FP under test three
times in a row, with the same random seed.

In a followup CL (http://review.skia.org/303479/) we will also leverage
this helper class to regenerate the FP under test with the same random
seed, but with a different input.

Change-Id: I1cd83082a949d555f7898970c8a1cc3002818286
Bug: skia:10384
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/303657
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>