Replace three mix() calls with one swizzled mix().

Not a big deal, just a tiny simplification.

Change-Id: I34e1404d79e22449f19a22ccf2cf6ffd98acf879
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/395727
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
1 file changed