Begin wrapping GrSmallPathRenderer atlas accesses

Eventually the small path renderer will have an atlas manager it
can only access through the flushState.

This is heading towards:
https://skia-review.googlesource.com/c/skia/+/307776 (Split the small path renderer into record-time and flush-time pieces)

Change-Id: Ie8ad7d421575548294c78dcb4623cb465952a07e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/308281
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed