UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

Steps to reproduce the problem:
1. Launch Chrome Browser on Kubuntu 18.04 LTS. Note this issue has been reported across many linux distributions. 
2. Open a tab that has video elements. 
3. Chrome will no longer let the computer's power management kick in. Even if Chrome is not in a visible workspace or if the said tab is not active.

What is the expected behavior?
The computer's power management should kick in if the Chrome tab with video elements is not visible or being used.

What went wrong?
Machine stays on for hours on hours because chrome won't let the power management kick in. 

This issue has been documented on the internet thoroughly over the last three years. There are open bugs against many linux distros and even open bugs against Chrome itself. We need some attention from Chrome developers. 

This bug is wasting so many hours of energy, across so many machines, needlessly.

Related bugs on Ubuntu and Chromium: 
https://bugs.chromium.org/p/chromium/issues/detail?id=654659
https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1600622
https://bugs.chromium.org/p/chromium/issues/detail?id=827528

Did this work before? N/A 

Chrome version: 71.0.3578.98  Channel: stable
OS Version: Kubuntu 18.04 LTS
Flash Version: 

Look at the number of people facing this issue. This issue is now 3 years old and reproducible starting from Ubuntu 16.04 LTS

https://www.reddit.com/r/linuxquestions/comments/4pvxx3/dbus_policy_to_deny_chrome_from_inhibiting_power/
https://productforums.google.com/forum/#!topic/chrome/EZpNDL4GzyU;context-place=forum/chrome
https://www.reddit.com/r/kde/comments/8srbah/inconsistent_screen_lock/
https://bbs.archlinux.org/viewtopic.php?id=238686