Tabs no longer converge on the position of the last closed tab like Chrome (so you can close a long series of tabs without moving the mouse). Plugin fix?

1) Open enough tabs force them to change width (compress horizontally). 2) attempt to close several tabs quickly. 3) get frustrated as the tabs automatically re-size to fill all the available horizontal space, moving the closing X button out of the way of the mouse, as opposed to the remaining tabs simply converging left, placing the next tab's X button where the previous one was. Firefox behaved this way in 11.x and now suddenly it doesn't. Slightly annoying...