This is exposed by an upcomging CL (https://codereview.chromium.org/2849523003/#)

- Have a payment method without a valid billing address
- Click on it in the payment method list UI to launch the editor
- Add a new billing address and save the credit card info
- Back on the main payment sheet, click on the payment method row

The payment method list still shows a warning that the credit card doesn't have a valid billing address.

Close the payment dialog completely, and reopen it, and now the credit card has a valid billing address.