Allow skimage expectations file to not exist.

If the file is not there, assume that all images are mismatches.
This allows running the test before the initial rebaseline.

R=epoger@google.com

Review URL: https://codereview.chromium.org/17448011

git-svn-id: http://skia.googlecode.com/svn/trunk@9690 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed