Chrome Version       : 68.0.3440.106
OS Version: Ubuntu 16.04

What steps will reproduce the problem?
1. open an awful lot of tabs, like several dozens
As expected, both the existing tabs and the new ones get narrower and narrower as you keep adding more
2. Place your cursor over the N-th tab where N is a small number (e.g. the 5th tab) and start quickly closing many tabs by always closing the one that is under your cursor (you may need to move the cursor a little bit, expectedly not at all)

What is the expected result?
Every time you close a tab, the ones next to it on the right will shift to the left of one position (and only the one that gets focus will grow a little bit if needed so that the "close" button fits), so there will be less tabs. If you keep closing them at a fast enough pace, they won't grow, and the empty space on the right will grow as tabs slide to the left. If you stop closing tabs for a few seconds, then all the tabs (both on the left and right) will grow and reclaim the empty space that you created on the right.
AT NO TIME, EVER, should tabs shrink. They should either grow, if you pause and give them time to, or remain the same size if you keep closing them relentlessly. But there's no reason why they should ever shrink, as you are only closing tabs and not adding new ones, ever.  


What happens instead of that?

At a certain point, all the tabs except the focused one start shrinking, which makes no sense, because the available unused space is increasing and the number of tabs is diminishing.


As you can see in screenshot 2, there are less tabs than in screenshot 1, yet they are significally narrower, as they have been shrinking while I closed a few of them.


UserAgentString: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36



 

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