Instead directly declare the parameters as they are "added to the list".

Change-Id: I3245b5834157eb9f443ceb5da47db231a237d673
Reviewed-on: https://chromium-review.googlesource.com/c/1270815Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56481}