Comment 4 for bug 876299

I'm hesitant to add a fixed minimum-size request in pixels to our code, as that doesn't scale well with different fonts and screen DPIs.

At the very least, we ought to be scaling this based upon the line-height of the font used to render the text, but I'm not immediately sure how to grab that in a non-kludgy way.

In the mean time, we should investigate whether the Ubuntu overlay scrollbar feature is robbing us of a convenient minimum size we ought to be allocated due to the adjacent "Add" button widget.