UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.18 Safari/537.36

Steps to reproduce the problem:
1. Checkout the following repo: https://github.com/stijnkoopal/bug-report-shadomdom-passwords
2. Run application (see Readme)
3. Fill in form with valid strings. 
4. See that Chrome does not ask to save password. (And it does not show a key in the right side of URL bar)
5. Switch to branch 'shady-dom'
6. Repeat step 3
7. See that Chrome asks for password

What is the expected behavior?
Chrome to ask to store password, even when the form is in a shadow-dom tree.

What went wrong?
Chrome does not ask for password.

Did this work before? N/A 

Chrome version: 63.0.3239.18  Channel: beta
OS Version: OS X 10.12.6
Flash Version: 

Version 63.0.3239.18 (Official Build) beta (64-bit)