add test for degenerate canvas dimension

Bug: skia:
Change-Id: Ib0532e706fbcdb126619301591ddc64910babdef
Reviewed-on: https://skia-review.googlesource.com/121341
Reviewed-by: Yuqian Li <liyuqian@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed