Handle degenerate viewMatrix in draw_shape_with_mask_filter

For the specific fuzz in question the viewMatrix is:

0 0 0
0 0 0
0 0 1

Bug:1174637
Change-Id: Ia07fe7255de7aff3df0c8cc11da7e90434392f29
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/368668
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
2 files changed