Fix two issues in transfer to test

1) Use buffer wider than texture when write pixels row bytes *is* supported
2) Fix buffer rowbytes/size calculation

Change-Id: I458010e75a42ada9b0fa9628fa0d2d4a3d823162
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229816
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed