UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Example URL:
https://s.codepen.io/betabong/debug/JOvQPK

Steps to reproduce the problem:
Open https://s.codepen.io/betabong/debug/JOvQPK
1. Enter any credentials and Submit
2. Save the password if you're asked (if not click on the key icon in the URL field)
3. Reload the page
4. Click the button "Add Input to DOM"

What is the expected behavior?
The only focus event logged should be: "Received focus: add of controls" 

What went wrong?
The autofill feature seems to observe the DOM and autofills whenever an input element is added to the DOM. Now that's fine, but it's not fine that the feature triggers focus events like a maniac, not on page load but especially not when the DOM changes.

(IMHO it should only trigger input and change events once)

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? Yes 61

Does this work in other browsers? Yes

Chrome version: 62.0.3202.94  Channel: stable
OS Version: OS X 10.13.1
Flash Version: 

The resulting problem can be quite severe actually, especially for websites that try to be good by caring about focus events for accessibility reasons. It's good practice to listen for focus events outside of flyouts for example and close the flyout if so.

You can visit https://www.swiss.com open the Login flyout and enter credentials (and enter and save the credentials). Now when you reload the page and try to open the flyout, it will close soon afterwards. Because it thinks that the user focused an element outside of the flyout.