Signing in via Google OAuth results in "Csrf detected" error

Summary

When attempting to sign in to Gitlab(.com) via Google OAuth, a "Csrf detected" error is presented.

Steps to reproduce

Attempt to sign in to Gitlab via Google OAuth.

What is the current bug behavior?

An error is presented.

What is the expected correct behavior?

A sign in is performed.

Links

Reported by user:
https://twitter.com/martomoreno/status/829712743154475008

cc @briann