Check whether aria-expanded attribute is defined

Source/core/accessibility/AXRenderObject.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 1721 matching lines @@
             break;
 
         containerParent = containerParent->parentObject();
     }
 
     // Post that the row count changed.
     if (containerParent)
         axObjectCache()->postNotification(containerParent, document(), AXObjectCacheImpl::AXRowCountChanged, true);
 
     // Post that the specific row either collapsed or expanded.
-    if (roleValue() == RowRole || roleValue() == TreeItemRole)
-        axObjectCache()->postNotification(this, document(), isExpanded() ? AXObjectCacheImpl::AXRowExpanded : AXObjectCacheImpl::AXRowCollapsed, true);
+    AccessibilityExpanded expanded = isExpanded();
+    if (!expanded)
+        return;
+
+    if (roleValue() == RowRole || roleValue() == TreeItemRole) {
+        AXObjectCacheImpl::AXNotification notification = AXObjectCacheImpl::AXRowExpanded;
+        if (expanded == ExpandedCollapsed)
+            notification = AXObjectCacheImpl::AXRowCollapsed;
+
+        axObjectCache()->postNotification(this, document(), notification, true);
+    }
 }
 
 void AXRenderObject::textChanged()
 {
     if (!m_renderer)
         return;
 
     Settings* settings = document()->settings();
     if (settings && settings->inlineTextBoxAccessibilityEnabled() && roleValue() == StaticTextRole)
         childrenChanged();
@@ skipping 643 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink