[csswg-drafts] [css-text-3] hanging-punctuation effect on inline/block bounds (#4222)

stantonma has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-text-3] hanging-punctuation effect on inline/block bounds ==
https://drafts.csswg.org/css-text-3/#hanging-punctuation-property

Hanging punctuation is defined to allow glyphs to display outside of the line box. However it's not clear if the bounds for things like border, background-color, and selection should include the overhang or not.

Safari's implementation includes the bounds if applied inline, but the overhang does not seem to affect the box bounds. This behavior is fine with me, but wondering if we should standardize it somewhere.

**Safari Rendered Output**

![Screen Shot 2019-08-19 at 3 45 53 PM](https://user-images.githubusercontent.com/51447838/63304632-8abd7380-c298-11e9-89d6-b4a8c3721420.png)

https://codepen.io/stantonm/pen/ZEzpJpY

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4222 using your GitHub account