Follow-up test from Ian's comments in https://golang.org/cl/35232
after submit.

Change-Id: Ifa504bd8d09e555c3c7738376199dfc9b99130cf
Reviewed-on: https://go-review.googlesource.com/35234
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>