GitLab

Also update some comments to refer to Http2String.

This CL lands server changes 189187480 by ahedberg and 190218258 by
diannahu.

BUG=488484

Change-Id: Iffc6a90651103954e2528f16a3d3f7e288d4f333
Reviewed-on: https://chromium-review.googlesource.com/978392Reviewed-by: Bence Béky <bnc@chromium.org>
Commit-Queue: Dianna Hu <diannahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545992}