concatTransform() can handle null images

Bug: oss-fuzz:51938
Change-Id: I20ca64a6afeba13f7440b84d9dae236c4c3e6ad0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/586326
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed