add inital gm for colorfilters

BUG=skia:
R=djsollen@google.com

Review URL: https://codereview.chromium.org/140393005

git-svn-id: http://skia.googlecode.com/svn/trunk@13346 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed