chromium/content/test/data/accessibility/html/tab-panel-expected-mac.txt

AXWebArea
++AXRadioButton AXSubrole=AXTabButton AXTitle='First Tab' AXValue=1
++AXRadioButton AXSubrole=AXTabButton AXTitle='Second Tab' AXValue=0
++AXRadioButton AXSubrole=AXTabButton AXTitle='Third Tab' AXValue=0
++AXGroup AXSubrole=AXTabPanel AXDescription='First Tab'
++++AXGroup
++++++AXStaticText AXValue='Content for the first panel, this should be read.'