multiple line breaks inside font tag with br

The following html will not rendered correctly:
```html

Line2

Line3

```
I know this is very ugly html. This is from Microsoft Outlook.

Output: (the browser on the right is chrome)

If you remove the first br tag (inside the div tag) it renders as expected

Start by reproducing the supplied Outlook HTML in the HTML-Renderer output and compare it with Chrome, focusing on the interaction between the first br inside div, subsequent line breaks, and the surrounding font tag. Done means the sample renders with the same line breaks as the expected browser output; the payload names no source files or tests.

索引モデルが issue の本文から書いたものです。