Comment 13 for bug 1823544

I've experienced same issue. Kept my machine running overnight with open gnome-shells.

On the morning GPU-Util was about 95% and memory usage ~500 mb for each tab

Cold start:
+-----------------------------------------------------------------------------+
| Processes: GPU Memory |
| GPU PID Type Process name Usage |
|=============================================================================|
| 0 1422 G /usr/lib/xorg/Xorg 73MiB |
| 0 1640 G /usr/bin/gnome-shell 118MiB |
| 0 4194 G /usr/lib/xorg/Xorg 379MiB |
| 0 4326 G /usr/bin/gnome-shell 257MiB |

System:
Distributor ID: Ubuntu
Description: Ubuntu 18.04.3 LTS
Release: 18.04
Codename: bionic

5.0.0-31-generic x86_64