menu: menu gets clipped when screen is too small

[Becky Gibson]

When in high contrast mode the font for the menu matches the high contrast mode menu size (because we use the menu keyword for the menuitem font), thus it is likely to be very large. If the screen isn't large enough to display the entire menu when I right click, the bottom menu items may get clipped by the bottom of the screen. Using the mouse, there is no way to scroll the bottom items into view. The work around is to use the keyboard. The same problem occurs when not in high contrast mode but is harder to reproduce - the browser size has to be very small.

If I make the browser size even smaller, the top of the menu does get adjusted but I haven't quite figured out what forces the top of the menu to be adjusted above the current mouse click point that invokes the menu.

[Becky Gibson]

since there is a workaround (using the keyboard) I am moving to 1.3

[Chris Mitchell]

reassign due to inactive committer. please triage accordingly.

[bill]

Duplicate of #10631.