Actually enable buffer->buffer transfer cap on D3D

Functionality was added here:
https://skia-review.googlesource.com/c/skia/+/550707

Bug: skia:13427
Bug: skia:12720
Change-Id: I23af4df9a5ecce01a46192f013cd733869085757
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/552677
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed