This updates the test runner to run all tests in both sloppy
and strict mode.

It also marks the test in the status file as failing in
sloppy mode even if all it does is marking the test as
[PASS, FAIL]. A future CL will have to validate that the
tests pass and fail in the correct mode.

Review URL: https://codereview.chromium.org/1136553008

Cr-Commit-Position: refs/heads/master@{#28879}