Update some logic to check mixed state of ARIA elements.

Source/modules/accessibility/AXObject.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 359 matching lines @@
 }
 
 AccessibilityButtonState AXObject::checkboxOrRadioValue() const
 {
     // If this is a real checkbox or radio button, AXRenderObject will handle.
     // If it's an ARIA checkbox or radio, the aria-checked attribute should be used.
 
     const AtomicString& result = getAttribute(aria_checkedAttr);
     if (equalIgnoringCase(result, "true"))
         return ButtonStateOn;
-    if (equalIgnoringCase(result, "mixed"))
+    if (equalIgnoringCase(result, "mixed")) {
+        AccessibilityRole role = ariaRoleAttribute();
+        if (role == RadioButtonRole || role == MenuItemRadioRole)
+            return ButtonStateOff;
         return ButtonStateMixed;
+    }
 
     return ButtonStateOff;
 }
 
 bool AXObject::ariaIsMultiline() const
 {
     return equalIgnoringCase(getAttribute(aria_multilineAttr), "true");
 }
 
 bool AXObject::ariaPressedIsPresent() const
@@ skipping 552 matching lines @@
         return ToggleButtonRole;
     if (ariaHasPopup())
         return PopUpButtonRole;
     // We don't contemplate RadioButtonRole, as it depends on the input
     // type.
 
     return ButtonRole;
 }
 
 } // namespace blink