Depending on the orientation, the source image may be row-major
or column-major; with positive or negative x/y-axis pitches.
Regardless of the orientation, the destination remains
row-major.

Bug: angleproject:4436
Bug: b/150329975
Change-Id: Ia1287f7036f07548d35128f1761feadf721cd78a
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2191425Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Commit-Queue: Ian Elliott <ianelliott@google.com>