[graphite] Add TextureInfo class.

Also adds the Mtl subclass as well

Bug: skia:12466
Change-Id: Ia3a81f33a00374a96765fde3a3442c5e13188ad1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/453719
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
7 files changed