Re-enable test testAlsoRunDisabledTests

The command line --all will be used in place of --also-run-disabled-tests,
which was removed in a previous CL. This CL also refactors gpu_integration_test_unittest.py
and provides documentation for pre submit checks which look for collisions
between test expectations.

Bug: chromium:937516
Change-Id: If1c3dd820da6fc72bb837a98be5f60972de1bf31
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1600612
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657617}
1 file changed