Can we specifically say in this comment that one of the browser idiosyncrasies we're normalizing is the selection of `br` elements in Blink (chrome/opera)?

Also, is it possible to change this so the extra work only happens in Chrome? We use `selected` a *lot* and I'm worried about the performance implications of doing this every time (especially for IE8 and IE7, who are sooo slow). Do you have any estimate on how much of a performance hit this causes for those browsers?