Show non-webkit test failures in the failure stream

-Remove ct-failing-builders and instead show all failures in the stream the
same way we do for webkit tests.
-Sort the failures in a group by step name then by test name.
-Do the dumb object --> model classes transition in small pieces to avoid blocking
getting a minimally viable product ready too much on completely doing this
refactoring.

The UI is not awesome, but I wanted to get the functionality in place first.

NOTRY=true
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/416673003

git-svn-id: svn://svn.chromium.org/blink/trunk@179194 bbb929c8-8fbe-4397-9dbb-9b2b20218538