Add tools/perf/contrib/orderfile/.

This will be used for orderfile generation benchmarks. More precisely,
they are thin wrappers around the system health benchmarks that make it
more convenient to run orderfile generation.

Bug: 843561
Change-Id: I5d3a2288d4f4a2f74004ef90f3cec0e4b44c7198
Reviewed-on: https://chromium-review.googlesource.com/1124161Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Matthew Cary <mattcary@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572181}

tools/perf/contrib/orderfile/OWNERS

+lizeb@chromium.org
+mattcary@chromium.org
+pasko@chromium.org