Add script to verify that image files exist for every actual_result checksum

Should help with https://code.google.com/p/skia/issues/detail?id=1410
(SkipBuildbotRuns)

R=epoger@google.com

Review URL: https://codereview.chromium.org/18743006

git-svn-id: http://skia.googlecode.com/svn/trunk@10017 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed