Fix issue with descendants of aria-activedescendant being marked as focusable.

third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp

 /*
  * Copyright (C) 2012, Google 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 1085 matching lines @@
 bool AXNodeObject::canSetFocusAttribute() const
 {
     Node* node = getNode();
     if (!node)
         return false;
 
     if (isWebArea())
         return true;
 
     // Children of elements with an aria-activedescendant attribute should be
-    // focusable if they have an ARIA role.
-    if (ariaRoleAttribute() != UnknownRole && ancestorExposesActiveDescendant())
+    // focusable if they have a (non-presentational) ARIA role.
+    if (!isPresentational() && ariaRoleAttribute() != UnknownRole && ancestorExposesActiveDescendant())
         return true;
 
     // NOTE: It would be more accurate to ask the document whether setFocusedNode() would
     // do anything. For example, setFocusedNode() will do nothing if the current focused
     // node will not relinquish the focus.
     if (isDisabledFormControl(node))
         return false;
 
     return node->isElementNode() && toElement(node)->supportsFocus();
 }
@@ skipping 1776 matching lines @@
     return placeholder;
 }
 
 DEFINE_TRACE(AXNodeObject)
 {
     visitor->trace(m_node);
     AXObject::trace(visitor);
 }
 
 } // namespace blink