Check whether aria-expanded attribute is defined

Source/core/accessibility/AXNodeObject.cpp

Index: Source/core/accessibility/AXNodeObject.cpp
diff --git a/Source/core/accessibility/AXNodeObject.cpp b/Source/core/accessibility/AXNodeObject.cpp
index 7a08650708dfe5bc8a2eaf8c3b83d960a40a2b44..c58a8cb3c6e0eebdbec1d4ccdc1bc6678bbe9263 100644
--- a/Source/core/accessibility/AXNodeObject.cpp
+++ b/Source/core/accessibility/AXNodeObject.cpp
@@ -709,14 +709,6 @@ bool AXNodeObject::isEnabled() const
     return !toElement(node)->isDisabledFormControl();
 }
 
-bool AXNodeObject::isExpanded() const
-{
-    if (equalIgnoringCase(getAttribute(aria_expandedAttr), "true"))
-        return true;
-
-    return false;
-}
-
 bool AXNodeObject::isIndeterminate() const
 {
     Node* node = this->node();
@@ -1101,6 +1093,21 @@ String AXNodeObject::ariaDescribedByAttribute() const
     return accessibilityDescriptionForElements(elements);
 }
 
+AccessibilityExpanded AXNodeObject::getExpandedAttr() const
+{
+    const AtomicString& expanded = getAttribute(aria_expandedAttr);
+    if (equalIgnoringCase(expanded, "true"))
+        return ExpandedExpanded;
+    if (equalIgnoringCase(expanded, "false"))
+        return ExpandedCollapsed;
+
+    return ExpandedUndefined;
+}
+
+AccessibilityExpanded AXNodeObject::ariaExpanded() const
+{
+    return getExpandedAttr();
+}
 
 String AXNodeObject::ariaLabeledByAttribute() const
 {