sk_spification of GrGpu creation.

Make GrContext::MakeGL take interface as sk_sp.

Make GrContext::MakeVulkan take GrVkBackendContext as sk_sp.

Change-Id: I13c22a57bd281c51738f503d9ed3418d35a466df
Reviewed-on: https://skia-review.googlesource.com/81842
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
22 files changed