Uses the activedescendant_changed event received from Blink to fire the right focus event

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

 /*
  * 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 47 matching lines @@
 #if ENABLE(ASSERT)
     bool m_initialized;
 #endif
 
     bool computeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const override;
     const AXObject* inheritsPresentationalRoleFrom() const override;
     virtual AccessibilityRole determineAccessibilityRole();
     virtual AccessibilityRole nativeAccessibilityRoleIgnoringAria() const;
     String accessibilityDescriptionForElements(HeapVector<Member<Element>> &elements) const;
     void alterSliderValue(bool increase);
-    AXObject* activeDescendant() const override;
+    AXObject* activeDescendant() override;
     String ariaAccessibilityDescription() const;
     String ariaAutoComplete() const;
     AccessibilityRole determineAriaRoleAttribute() const;
     void accessibilityChildrenFromAttribute(QualifiedName attr, AXObject::AXObjectVector&) const;
 
     bool hasContentEditableAttributeSet() const;
     bool isTextControl() const override;
     // This returns true if it's focusable but it's not content editable and it's not a control or ARIA control.
     bool isGenericFocusableElement() const;
     HTMLLabelElement* labelForElement(const Element*) const;
@@ skipping 133 matching lines @@
     bool isNativeCheckboxInMixedState() const;
     String textFromDescendants(AXObjectSet& visited, bool recursive) const override;
     String nativeTextAlternative(AXObjectSet& visited, AXNameFrom&, AXRelatedObjectVector*, NameSources*, bool* foundTextAlternative) const;
     float stepValueForRange() const;
     bool isDescendantOfElementType(const HTMLQualifiedName& tagName) const;
 };
 
 } // namespace blink
 
 #endif // AXNodeObject_h