GitLab

Make payment tests use two argument ResponseHeader manipulation calls

We want to get rid of the single argument AddHeader() method as the two
argument AddHeader() and SetHeader() methods are safer and more flexible.

Bug: 1068194
Change-Id: Id950858f00c584a99af69faab6f70ed4c984db9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2150009
Auto-Submit: Matt Menke <mmenke@chromium.org>
Reviewed-by: Danyao Wang <danyao@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759406}