UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36

Steps to reproduce the problem:
1. Inspect element.
2. Under Styles tab on right, add the hyphens property to `element.style`.
3. Press tab so you're on the value box.

What is the expected behavior?
Dropdown to list all possible (named) values

What went wrong?
"auto" is missing. The dropdown shows inherit, initial, manual, none, unset. Auto is a valid value, which Chrome supports and works fine, but it's not in the list.

Did this work before? N/A 

Chrome version: 63.0.3239.132  Channel: stable
OS Version: OS X 10.13.2
Flash Version: 

Don't know if there are missing values for other properties, I checked a few and they appeared to be fine but I don't know every value off-hand.