mdDialog collapses to upper left if targetEvent element isn't visible when it closes

[dozingcat]

Demo: http://codepen.io/anon/pen/BNYpEZ . If you click on the "Open dialog" button at the top right, the dialog animation will correctly open from and close to the button. If you hover over the "Menu" label and then click the revealed "Open from menu" link, the dialog will open from the menu item as expected, but when closing the animation goes to the upper left, presumably because the element it opened from is now hidden. I would expect that in that case the dialog animation would go to the same location that it opened from.