Clip the SkAntiRect because of possible tilings

Otherwise, the AndroidShadow will crash or draw incorrectly
for the threaded backend with # tiles >= 3.

Bug: skia:
Change-Id: If3c3b41f3576b1c44178d6343626e99be64e766b
Reviewed-on: https://skia-review.googlesource.com/122953
Commit-Queue: Yuqian Li <liyuqian@google.com>
Auto-Submit: Yuqian Li <liyuqian@google.com>
Reviewed-by: Cary Clark <caryclark@google.com>
1 file changed