remove reference to (deleted) SkKernel33MaskFilter

BUG=skia:
R=caryclark@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/281163002

git-svn-id: http://skia.googlecode.com/svn/trunk@14738 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed