> To be sharp: the WebAPI team (hi @mounirlamouri !) recommended not to set the lang/dir attributes “magically” with l10n.js. So even if l10n.js supported frames, we’d still have to write most of this code to set the lang/dir attributes of these framed documents.

This is correct. The reason being that you can have a document like this:
```html
<!DOCTYPE html>
<html>
<body>
<div data-l10n='foo'></div>
<div>Hi, this text is in English</div>
</body>
<html>
```
A good document would make sure that the second div has ```lang='en'``` but we can't assume that. I think the best think l10n.js can do is to set ```lang``` and ```dir``` on the elements it has translated.