drive-by change: fix wrong typing in CSA.

Change-Id: I9234306e8568a64157b44a86a58f09e65116b298
Reviewed-on: https://chromium-review.googlesource.com/1172583
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55093}