Worst of all is that closing the downloads bar actually makes the browser window smaller! It actually doesn't -- or at least, it doesn't seem to on the Dev Cha

Worst of all is that closing the downloads bar actually makes the browser window smaller! It actually doesn't -- or at least, it doesn't seem to on the Dev Channel or Canary. If there's enough screen real estate, the downloads panel grows out of the bottom of the window, and shrinks away when dismissed. The viewport retains the same dimensions before and after. If there isn't enough space below the window, the panel does indeed overlay the bottom ~47px of content, but in that case, dismissing it doesn't change the size of the window, restoring the viewport to its previous size. That's the most frustrating thing about Chrome: it's inconsistently polished, and in many cases, it feels like its relationship to ChromeOS is akin to the tail wagging the dog.