Closes #21279

Change-Id: I84d6b168a684fa9f3c046028d0c9f00292d7c110
Reviewed-on: https://go-review.googlesource.com/61132Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>