Direct3D: More interface changes to support mipmap generation.

Adds aliasing barriers, a texture copy convenience routine, and
subresource support in texture resource state transitions. Also
some minor formatting cleanup.

Change-Id: Ic8ba504350a3f954a21d24a214d9cceb3f5fc44d
Bug: skia:10446
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/403600
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
6 files changed