More SkAutoPixmapStorage

A left over code review request

Change-Id: Ib58abaee4761d14b8ec67f88dc903ac1ed06a58e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/232016
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
3 files changed