The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ba302109b0fafb5517c6ae29f5ae47735755c7da

commit ba302109b0fafb5517c6ae29f5ae47735755c7da
Author: eugenebut <eugenebut@chromium.org>
Date: Wed Oct 12 23:13:13 2016

[mac] Fixed window buttons positioning on Sierra.

Set buttons' bottomAnchor to superview bottomAnchor.

BUG= 655185 , 605219 

Review-Url: https://codereview.chromium.org/2412903003
Cr-Commit-Position: refs/heads/master@{#424900}

[modify] https://crrev.com/ba302109b0fafb5517c6ae29f5ae47735755c7da/base/mac/sdk_forward_declarations.h
[modify] https://crrev.com/ba302109b0fafb5517c6ae29f5ae47735755c7da/chrome/browser/ui/cocoa/framed_browser_window.mm