Update Perlin noise factories to handle no octaves

Bug: b/238754013
Change-Id: I280fff6145180b5d5056acbf6f423018cde18e28
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/653280
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed