Adds functionality to Dawn and Tint to rotate and flip-Y external
textures through the shader transform. Tests are included.
Bug: chromium:1316671
Change-Id: I40a6b67eaeb2a348f469e4879eeb585bc40537b2
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/110181
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Brandon1 Jones <brandon1.jones@intel.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
85ceb08d5c