Add null check for non-cached shadows.

Change-Id: I8015a026d4bb54f04ee86fca0d4b0be3bc1d9bd8
Reviewed-on: https://skia-review.googlesource.com/23123
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
1 file changed