[DevTools] Audits: Update interface for setting Lighthouse flags

Bug: 914387
Change-Id: Ice3e79cc8527d687ffdfe87a22ddf8a459230ef2
Reviewed-on: https://chromium-review.googlesource.com/c/1374196
Reviewed-by: Paul Irish <paulirish@chromium.org>
Reviewed-by: Erik Luo <luoe@chromium.org>
Commit-Queue: Paul Irish <paulirish@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616360}
1 file changed