Merge 94716 - Changes to aria-hidden don't change VO navigation

Source/WebCore/accessibility/AccessibilityRenderObject.cpp

 /*
 * Copyright (C) 2008 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 1683 matching lines @@
 }
     
 bool AccessibilityRenderObject::ariaIsHidden() const
 {
     if (equalIgnoringCase(getAttribute(aria_hiddenAttr), "true"))
         return true;
     
     // aria-hidden hides this object and any children
     AccessibilityObject* object = parentObject();
     while (object) {
-        if (object->isAccessibilityRenderObject() && equalIgnoringCase(static_cast<AccessibilityRenderObject*>(object)->getAttribute(aria_hiddenAttr), "true"))
+        if (equalIgnoringCase(object->getAttribute(aria_hiddenAttr), "true"))
             return true;
         object = object->parentObject();
     }
 
     return false;
 }
 
 bool AccessibilityRenderObject::isDescendantOfBarrenParent() const
 {
     for (AccessibilityObject* object = parentObject(); object; object = object->parentObject()) {
@@ skipping 1603 matching lines @@
     bool sentChildrenChanged = false;
     
     // Go up the accessibility parent chain, but only if the element already exists. This method is
     // called during render layouts, minimal work should be done. 
     // If AX elements are created now, they could interrogate the render tree while it's in a funky state.
     // At the same time, process ARIA live region changes.
     for (AccessibilityObject* parent = this; parent; parent = parent->parentObjectIfExists()) {
         if (!parent->isAccessibilityRenderObject())
             continue;
         
-        AccessibilityRenderObject* axParent = static_cast<AccessibilityRenderObject*>(parent);
+        AccessibilityRenderObject* axParent = toAccessibilityRenderObject(parent);
         
         // Send the children changed notification on the first accessibility render object ancestor.
         if (!sentChildrenChanged) {
             axObjectCache()->postNotification(axParent->renderer(), AXObjectCache::AXChildrenChanged, true);
             sentChildrenChanged = true;
         }
         
         // Only do work if the children haven't been marked dirty. This has the effect of blocking
         // future live region change notifications until the AX tree has been accessed again. This
         // is a good performance win for all parties.
@@ skipping 61 matching lines @@
         return;
     
     m_haveChildren = true;
     
     if (!canHaveChildren())
         return;
     
     // add all unignored acc children
     for (RefPtr<AccessibilityObject> obj = firstChild(); obj; obj = obj->nextSibling()) {
         if (obj->accessibilityIsIgnored()) {
-            obj->updateChildrenIfNecessary();
+
+            // If the parent is asking for this child's children, then either it's the first time (and clearing is a no-op), 
+            // or its visibility has changed. In the latter case, this child may have a stale child cached. 
+            // This can prevent aria-hidden changes from working correctly. Hence, whenever a parent is getting children, ensure data is not stale.
+            obj->clearChildren();
+            
             AccessibilityChildrenVector children = obj->children();
             unsigned length = children.size();
             for (unsigned i = 0; i < length; ++i)
                 m_children.append(children[i]);
         } else {
             ASSERT(obj->parentObject() == this);
             m_children.append(obj);
         }
     }
     
@@ skipping 329 matching lines @@
 
     m_roleForMSAA = msaaRoleForRenderer(m_renderer);
 
     if (m_roleForMSAA == UnknownRole)
         m_roleForMSAA = roleValue();
 
     return m_roleForMSAA;
 }
 
 } // namespace WebCore