Introduce new API orientation() to expose aria-orientation correctly.

Source/web/WebAXObject.cpp

Index: Source/web/WebAXObject.cpp
diff --git a/Source/web/WebAXObject.cpp b/Source/web/WebAXObject.cpp
index 8719bfa6788e9afaf87c935d8bb822acf65f7ef4..b2d7e9d65b68dfd793236f3d736913516fab64c8 100644
--- a/Source/web/WebAXObject.cpp
+++ b/Source/web/WebAXObject.cpp
@@ -397,6 +397,14 @@ bool WebAXObject::isVertical() const
     return m_private->orientation() == AccessibilityOrientationVertical;
 }
 
+WebAXOrientation WebAXObject::orientation() const
+{
+    if (isDetached())
+        return WebAXOrientationUndefined;
+
+    return static_cast<WebAXOrientation>(m_private->orientation());
+}
+
 bool WebAXObject::isVisible() const
 {
     if (isDetached())