If this sticks without causing a performance regression then it'd be
good to rework it on top of SkRefCnt, using it's internal_dispose()
mechanism to return the resource to the cache.
Change-Id: Ic43633ac6421a1e20f00aefa27f78b3eb0e89e8f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/243416
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>