Fixing a clusterfuzz found issue

BUG=378175
R=reed@google.com, sugoi@google.com

Author: sugoi@chromium.org

Review URL: https://codereview.chromium.org/306033003

git-svn-id: http://skia.googlecode.com/svn/trunk/src@14983 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed