chromium/content/test/data/accessibility/aom/aom-live-region-expected-mac.txt

AXWebArea
++AXGroup AXSubrole=AXApplicationMarquee AXARIALive='off'
++AXGroup AXSubrole=AXApplicationMarquee AXARIALive='polite'
++AXGroup AXSubrole=AXApplicationStatus AXARIALive='assertive'
++AXGroup AXSubrole=AXApplicationAlert AXARIALive='assertive'