Return table headers for aria tables.

Source/modules/accessibility/AXTableColumn.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 54 matching lines @@
     // this will be filled in when addChildren is called
     return m_columnRect;
 }
 
 void AXTableColumn::headerObjectsForColumn(AccessibilityChildrenVector& headers)
 {
     if (!m_parent)
         return;
 
     RenderObject* renderer = m_parent->renderer();
-    if (!renderer || !renderer->isTable())
+    if (!renderer)
+        return;
+
+    if (!m_parent->isAXTable())
+        return;
+
+    if (toAXTable(m_parent)->isAriaTable()) {
+        AccessibilityChildrenVector columnChildren = children();
+        unsigned childrenCount = columnChildren.size();
+        for (unsigned i = 0; i < childrenCount; i++) {
+            AXObject* cell = columnChildren[i].get();
+            if (cell->roleValue() == ColumnHeaderRole)
+                headers.append(cell);
+        }
+        return;
+    }
+
+    if (!renderer->isTable())
         return;
 
     LayoutTable* table = toLayoutTable(renderer);
     LayoutTableSection* tableSection = table->topSection();
     for (; tableSection; tableSection = table->sectionBelow(tableSection, SkipEmptySections)) {
         unsigned numRows = tableSection->numRows();
         for (unsigned r = 0; r < numRows; r++) {
             LayoutTableCell* layoutCell = tableSection->primaryCellAt(r, m_columnIndex);
             if (!layoutCell)
                 continue;
@@ skipping 124 matching lines @@
         // make sure the last one isn't the same as this one (rowspan cells)
         if (m_children.size() > 0 && m_children.last() == cell)
             continue;
 
         m_children.append(cell);
         m_columnRect.unite(cell->elementRect());
     }
 }
 
 } // namespace blink