Make GrSurface::MakeDeferred return sk_sp<GrTextureProxy>

This should make upcoming changes less tedious

Change-Id: I313ae9df724f109a64cf5708a974e8bfeb963025
Reviewed-on: https://skia-review.googlesource.com/9183
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
18 files changed