paper-dropdown-menu doesn't close after tapping the selected item

[mgiuffrida]

Fiddle: https://jsfiddle.net/j4rfjasf/

Start with a paper-dropdown-menu with nothing selected, as in the fiddle.

Steps:

1. Click the paper-dropdown-menu; the menu/listbox opens.
2. Click an item; the menu/listbox closes.
3. Click the dropdown again; the menu/listbox opens.
4. Click the same item as in 2, which is now bold.

Expected: The menu closes. Actual: Nothing happens.

Compare with native <select> behavior, which closes after tapping any item, even if that item is already selected.

[valdrinkoshi]

This looks like a duplicate of https://github.com/PolymerElements/paper-dropdown-menu/issues/72