Pass GrBackendFormat to GrGpu::onCreateTexture and use it to determine
texture format in backend API.

Bug: skia:6718
Change-Id: Ib224efdf0c4833618d574bc13f48ec04595df282
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/233299
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
12 files changed