GitLab

Replace a few usages of base::Callback with base::OnceCallback, and
update the corresponding base::Binds with base::BindOnce.

TEST=Triggered a ping twice for the same page, one with and one without
this change. The generated features were the same.

Bug: 933537
Change-Id: Ib9e5454be2e67342868b00af83a58b16cde6c163
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1489423Reviewed-by: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638341}