UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3153.2 Safari/537.36

Example URL:
http://nursing.hsc.wvu.edu/

Steps to reproduce the problem:
1. Go to http://nursing.hsc.wvu.edu/
2. Scroll down to "Connect with us" and look at social icons
3. If you change the border radius to 49.9999% it won't be a block. But 50% or more, and it defaults to a square box-shadow.

What is the expected behavior?
The box-shadow should display with the correct RGBA transparency and roundness of the element it is providing a box-shadow to.

What went wrong?
Border-radius of 50% or more, paired with a box-shadow causes the box-shadow to default to a square and not a circle.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? Yes 59.0.3

Does this work in other browsers? Yes

Chrome version: 61.0.3153.2  Channel: dev
OS Version: 10.0
Flash Version: