I had accidentally disabled a headline feature at the last second. :(

Fixes #14391

Change-Id: I1992c9b801072b7538b95c55242be174075ff932
Reviewed-on: https://go-review.googlesource.com/19672Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/22035Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>