diff -r 000000000000 -r 6474c204b198 accessible/src/generic/TableCellAccessible.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/generic/TableCellAccessible.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TableCellAccessible.h"
+
+#include "Accessible-inl.h"
+#include "TableAccessible.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+void
+TableCellAccessible::RowHeaderCells(nsTArray<Accessible*>* aCells)
+{
+  uint32_t rowIdx = RowIdx(), colIdx = ColIdx();
+  TableAccessible* table = Table();
+  if (!table)
+    return;
+
+  // Move to the left to find row header cells
+  for (uint32_t curColIdx = colIdx - 1; curColIdx < colIdx; curColIdx--) {
+    Accessible* cell = table->CellAt(rowIdx, curColIdx);
+    if (!cell)
+      continue;
+
+    // CellAt should always return a TableCellAccessible (XXX Bug 587529)
+    TableCellAccessible* tableCell = cell->AsTableCell();
+    NS_ASSERTION(tableCell, "cell should be a table cell!");
+    if (!tableCell)
+      continue;
+
+    // Avoid addding cells multiple times, if this cell spans more columns
+    // we'll get it later.
+    if (tableCell->ColIdx() == curColIdx && cell->Role() == roles::ROWHEADER)
+      aCells->AppendElement(cell);
+  }
+}
+
+void
+TableCellAccessible::ColHeaderCells(nsTArray<Accessible*>* aCells)
+{
+  uint32_t rowIdx = RowIdx(), colIdx = ColIdx();
+  TableAccessible* table = Table();
+  if (!table)
+    return;
+
+  // Move up to find column header cells
+  for (uint32_t curRowIdx = rowIdx - 1; curRowIdx < rowIdx; curRowIdx--) {
+    Accessible* cell = table->CellAt(curRowIdx, colIdx);
+    if (!cell)
+      continue;
+
+    // CellAt should always return a TableCellAccessible (XXX Bug 587529)
+    TableCellAccessible* tableCell = cell->AsTableCell();
+    NS_ASSERTION(tableCell, "cell should be a table cell!");
+    if (!tableCell)
+      continue;
+
+    // Avoid addding cells multiple times, if this cell spans more rows
+    // we'll get it later.
+    if (tableCell->RowIdx() == curRowIdx && cell->Role() == roles::COLUMNHEADER)
+      aCells->AppendElement(cell);
+  }
+}