Wow, what a screenshot.  I'm hoping that the testing team can find a machine we have around that can reproduce it.

Tried checking the issue on reported chrome version 67.0.3396.62 using Ubuntu 14.04 and Ubuntu 17.10 with 4GB and 8GB RAM respectively each with the below mentioned steps.
1. Launched Chrome
2. Opened few tabs
3. Navigated to the URLs present in the tabs multiple times.
We didn't observe any unusual UI when repeating the above steps. Hence removing Needs-TestConfirmation.
Note: As of now we do not have Ubuntu 18.04 bionic, with 8 gigabytes of RAM to test and confirm the issue on that specific environment

As per comment#3 as the issue is not reproducible at TE end and as this issue is reported on Ubuntu 18.04, adding TE-Hardware-Dependency label and requesting the appropriate team to look into this issue and help in further triaging.

Thanks.!

phenixb4631@, are still experiencing this?  I'm hoping that you say it's fixed :-), as we haven't been able to reproduce it on our end... 

No, it still happens to me, even on Chrome 68.

I don't think I shared this previously, but my work computer is an HP Omen
that came pre-installed with Windows 10. I don't remember the exact model
(I'm at home right now), but I do know the hard drive has been swapped out
for a solid state drive so that I could install Ubuntu without harming the
Windows 10 drive. I don't think any other hardware changes were made beyond
that.

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

estade@, how do we handle weird UI things like this, that might or might not be related to a particular Linux flavor/version?  Can you help?

I think this bug report is not just about a particular linux flavor, but a particular chromium flavor (Ubuntu Chromium in this case). The typical MO for Linux UI and integration concerns is to hand over to thomasanderson@.

To phenixb4631@, does this repro with Google Chrome?

Chrome is not available on Ubuntu, only Windows, macOS, and Android, I
thought. I knew this because I once tried to use Chrome's Remote Desktop,
which is not available with Chromium.

I would try using Chromium 69, but I don't think Ubuntu's package manager
sees it yet. Maybe tomorrow.

Google Chrome is available on Linux in .deb or .rpm format.

I figured it out. As a closed source application, Chrome requires a
different procedure to install than Chromium.

So far, I haven't run into this bug on Chrome 69, but I will reply again if
I do.

Thanks. I believe the bug tracker you're looking for is https://launchpad.net/ubuntu/+source/chromium-browser/+bugs