Move resourceProvider accessor to GrContextPriv

Change-Id: I5cddd620a7ec4b006b7359864ede58e9d4dd684e
Reviewed-on: https://skia-review.googlesource.com/94340
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
40 files changed