make growToInclude private

Bug: skia:
Change-Id: Id55344ba2f33563d22c2bf4d5829a9a31095a47d
Reviewed-on: https://skia-review.googlesource.com/92143
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Cary Clark <caryclark@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
9 files changed