skdiff: internally track lists of ALL result types, not just baseMissing and comparisonMissing

This does not change skdiff output at all; verified using tools/tests/run.sh
Review URL: https://codereview.appspot.com/6260057

git-svn-id: http://skia.googlecode.com/svn/trunk@4096 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed