Add GrGpuTextureProxyRef

Basically a GrTextureProxified clone of GrGpuResourceRef

Change-Id: I8772550bb867ef2cf2d53efef0a0346bb7c90eb6
Reviewed-on: https://skia-review.googlesource.com/15221
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
3 files changed