UserAgent: Mozilla/5.0 (X11; CrOS x86_64 9592.71.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.80 Safari/537.36
Platform: 9592.71.0 (Official Build) beta-channel samus

Steps to reproduce the problem:
1. Open two partially overlapping windows a Chrome window or tab on a Chromebook
2. With a USB mouse, middle click the title area

What is the expected behavior?
Middle clicking the title area should bring the window to back in the order (like on Linux, see https://youtu.be/Quw5ne89gIg).

What went wrong?
Not implemented.

Did this work before? N/A 

Chrome version: 60.0.3112.80  Channel: n/a
OS Version: 9592.71.0
Flash Version: