It was removed in upstream Chrome https://codereview.chromium.org/2016863004

Rather than update to the latest version, make the minimal change for Go 1.7 and
change the "showToUser" boolean from true to false.

Tested by hand that it goes away after this change.

Updates #16247

Change-Id: I051f49da878e554b1a34a88e9abc70ab50e18780
Reviewed-on: https://go-review.googlesource.com/25117Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>