Follow-up from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21344#note_97035185: We have an [old frontend testing guide](https://docs.gitlab.com/ce/development/testing_guide/frontend_testing.html) and a [new one](https://docs.gitlab.com/ce/development/new_fe_guide/development/testing.html). The old one needs to be removed and the missing pieces added to the new one.