roll GN

up to https://gn-review.googlesource.com/c/gn/+/8920

Change-Id: Ibf69abea267f092fe1bcfed3b7c02a8935223e36
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/296705
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed