add release-mode checks for null, at least for a while

BUG=skia:
R=bungeman@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/263883006

git-svn-id: http://skia.googlecode.com/svn/trunk@14552 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed