Remove GrTGpuResourceRef specializations

This template is only used for GrBuffers now.

Change-Id: Ia9e95576b01124657e64007231fbc0a83276e13f
Reviewed-on: https://skia-review.googlesource.com/19484
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
7 files changed