Update texel_subset_* GMs.

Draw placeholder gray rectangles rather than omitting cols/rows.

Swap x and y mode iteration so they correspond with GM layout.

Change-Id: I3c2d95bcd5d684f5a5a99cb677c326864e13f252
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/270641
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
1 file changed