Re: [webcomponents] [Custom Elements]: Custom elements should be display: block by default (#224)

Having stated my position, if we end up going with the route of change `display` value upon `defineElement` (perhaps due to support by Mozilla/Microsoft), then we should just define `:defined` instead of `:unresolved` (see the issue #418) and add the following rule to the default UA stylesheet:

```css
:defined { display: block }
```

Again, my preference is not to do this, and keep `display: inline` as the default value.

---
Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/224#issuecomment-193654846