UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Example URL:
https://jsfiddle.net/9zokhzj3/

Steps to reproduce the problem:
1. Open https://jsfiddle.net/9zokhzj3/

What is the expected behavior?
No horizontal scrollbar is displayed.

What went wrong?
The right header cell has 'none' border, while right body cell has 1px border. This difference confuses the browser when it determines the table width. In reality the table is wider hence scrollbar is displayed.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 57.0.2987.133  Channel: stable
OS Version: 10.0
Flash Version: Shockwave Flash 25.0 r0

It works in both FF and IE.