Only test processors code left. It enabled to move more stuff to
the base runner, like progress indicators creation.

Bug: v8:6917
Change-Id: Ie6dd211cec561a07d92bcc4431ea88eb1842c8fa
Reviewed-on: https://chromium-review.googlesource.com/897624Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michał Majewski <majeski@google.com>
Cr-Commit-Position: refs/heads/master@{#51030}