We augment the DoTexSubImage() call for the desktop GL fast path
for compressed textures (upload in a single call where possible).
Bug: dawn:684
Change-Id: Id67c39b1efbc8b435b58064cad66a55c153ce675
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/47240
Commit-Queue: Stephen White <senorblanco@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>