chromium/content/test/data/accessibility/html/offscreen-select-expected-win.txt

ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE
++ROLE_SYSTEM_COMBOBOX value='Onscreen 1' COLLAPSED FOCUSABLE HASPOPUP
++ROLE_SYSTEM_COMBOBOX value='Offscreen 1' COLLAPSED OFFSCREEN FOCUSABLE HASPOPUP