[Dawn] Add YCbCr info to DawnTextureSpec

Ensures that YCbCr info will be preserved when going back and forth
between DawnTextureInfo and TextureInfo.

Bug: b/41488897
Change-Id: Id915c5937fc15e45a3af8f8ca86aa1c5661c741e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/863356
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Nicolette Prevost <nicolettep@google.com>
Commit-Queue: Colin Blundell <blundell@chromium.org>
2 files changed