diff --git a/accessible/src/msaa/ARIAGridAccessibleWrap.cpp b/accessible/src/msaa/ARIAGridAccessibleWrap.cpp
index d95bd971a97d..0f4f20255224 100644
--- a/accessible/src/msaa/ARIAGridAccessibleWrap.cpp
+++ b/accessible/src/msaa/ARIAGridAccessibleWrap.cpp
@@ -21,6 +21,12 @@ IMPL_IUNKNOWN_INHERITED1(ARIAGridAccessibleWrap,
                          AccessibleWrap,
                          ia2AccessibleTable)
 
+void
+ARIAGridAccessibleWrap::Shutdown()
+{
+  ia2AccessibleTable::mTable = nullptr;
+  ARIAGridAccessible::Shutdown();
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // ARIAGridCellAccessibleWrap
diff --git a/accessible/src/msaa/ARIAGridAccessibleWrap.h b/accessible/src/msaa/ARIAGridAccessibleWrap.h
index 1ebc2fed8128..7babc5843d7f 100644
--- a/accessible/src/msaa/ARIAGridAccessibleWrap.h
+++ b/accessible/src/msaa/ARIAGridAccessibleWrap.h
@@ -24,13 +24,15 @@ class ARIAGridAccessibleWrap : public ARIAGridAccessible,
 {
 public:
   ARIAGridAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
-    ARIAGridAccessible(aContent, aDoc) {}
+    ARIAGridAccessible(aContent, aDoc), ia2AccessibleTable(this) {}
 
   // IUnknown
   DECL_IUNKNOWN_INHERITED
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
+
+  virtual void Shutdown() MOZ_OVERRIDE;
 };
 
 /**
diff --git a/accessible/src/msaa/HTMLTableAccessibleWrap.cpp b/accessible/src/msaa/HTMLTableAccessibleWrap.cpp
index c0a3d5661e2d..a87cfea0bb5f 100644
--- a/accessible/src/msaa/HTMLTableAccessibleWrap.cpp
+++ b/accessible/src/msaa/HTMLTableAccessibleWrap.cpp
@@ -20,6 +20,12 @@ IMPL_IUNKNOWN_INHERITED1(HTMLTableAccessibleWrap,
                          AccessibleWrap,
                          ia2AccessibleTable)
 
+void
+HTMLTableAccessibleWrap::Shutdown()
+{
+  ia2AccessibleTable::mTable = nullptr;
+  HTMLTableAccessible::Shutdown();
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // HTMLTableCellAccessibleWrap
diff --git a/accessible/src/msaa/HTMLTableAccessibleWrap.h b/accessible/src/msaa/HTMLTableAccessibleWrap.h
index 84df5eaa56de..55529db2e90a 100644
--- a/accessible/src/msaa/HTMLTableAccessibleWrap.h
+++ b/accessible/src/msaa/HTMLTableAccessibleWrap.h
@@ -25,13 +25,15 @@ class HTMLTableAccessibleWrap : public HTMLTableAccessible,
 {
 public:
   HTMLTableAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
-    HTMLTableAccessible(aContent, aDoc) {}
+    HTMLTableAccessible(aContent, aDoc), ia2AccessibleTable(this)  {}
 
   // IUnknown
   DECL_IUNKNOWN_INHERITED
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
+
+  virtual void Shutdown() MOZ_OVERRIDE;
 };
 
 
diff --git a/accessible/src/msaa/XULListboxAccessibleWrap.cpp b/accessible/src/msaa/XULListboxAccessibleWrap.cpp
index 1d744871ac0e..d9f768a90740 100644
--- a/accessible/src/msaa/XULListboxAccessibleWrap.cpp
+++ b/accessible/src/msaa/XULListboxAccessibleWrap.cpp
@@ -11,12 +11,6 @@ using namespace mozilla::a11y;
 // XULListboxAccessibleWrap
 ////////////////////////////////////////////////////////////////////////////////
 
-XULListboxAccessibleWrap::
-  XULListboxAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
-  XULListboxAccessible(aContent, aDoc)
-{
-}
-
 NS_IMPL_ISUPPORTS_INHERITED0(XULListboxAccessibleWrap,
                              XULListboxAccessible)
 
@@ -25,6 +19,12 @@ IMPL_IUNKNOWN_QUERY_CLASS_COND(ia2AccessibleTable, IsMulticolumn());
 IMPL_IUNKNOWN_QUERY_CLASS(AccessibleWrap)
 IMPL_IUNKNOWN_QUERY_TAIL
 
+void
+XULListboxAccessibleWrap::Shutdown()
+{
+  ia2AccessibleTable::mTable = nullptr;
+  XULListboxAccessible::Shutdown();
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // XULListCellAccessibleWrap
diff --git a/accessible/src/msaa/XULListboxAccessibleWrap.h b/accessible/src/msaa/XULListboxAccessibleWrap.h
index 389c30278a9a..75f08b7e18fb 100644
--- a/accessible/src/msaa/XULListboxAccessibleWrap.h
+++ b/accessible/src/msaa/XULListboxAccessibleWrap.h
@@ -22,13 +22,16 @@ class XULListboxAccessibleWrap : public XULListboxAccessible,
                                  public ia2AccessibleTable
 {
 public:
-  XULListboxAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc);
+  XULListboxAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
+    XULListboxAccessible(aContent, aDoc), ia2AccessibleTable(this) {}
 
   // IUnknown
   DECL_IUNKNOWN_INHERITED
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
+
+  virtual void Shutdown() MOZ_OVERRIDE;
 };
 
 /**
diff --git a/accessible/src/msaa/XULTreeGridAccessibleWrap.cpp b/accessible/src/msaa/XULTreeGridAccessibleWrap.cpp
index d327d173394b..233eac562fbd 100644
--- a/accessible/src/msaa/XULTreeGridAccessibleWrap.cpp
+++ b/accessible/src/msaa/XULTreeGridAccessibleWrap.cpp
@@ -11,12 +11,6 @@ using namespace mozilla::a11y;
 // XULTreeGridAccessibleWrap
 ////////////////////////////////////////////////////////////////////////////////
 
-XULTreeGridAccessibleWrap::
-  XULTreeGridAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
-  XULTreeGridAccessible(aContent, aDoc)
-{
-}
-
 NS_IMPL_ISUPPORTS_INHERITED0(XULTreeGridAccessibleWrap,
                              XULTreeGridAccessible)
 
@@ -24,6 +18,12 @@ IMPL_IUNKNOWN_INHERITED1(XULTreeGridAccessibleWrap,
                          AccessibleWrap,
                          ia2AccessibleTable)
 
+void
+XULTreeGridAccessibleWrap::Shutdown()
+{
+  ia2AccessibleTable::mTable = nullptr;
+  XULTreeGridAccessible::Shutdown();
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // XULTreeGridCellAccessibleWrap
diff --git a/accessible/src/msaa/XULTreeGridAccessibleWrap.h b/accessible/src/msaa/XULTreeGridAccessibleWrap.h
index 44aaf8e7ffcf..c56dddbced18 100644
--- a/accessible/src/msaa/XULTreeGridAccessibleWrap.h
+++ b/accessible/src/msaa/XULTreeGridAccessibleWrap.h
@@ -22,13 +22,16 @@ class XULTreeGridAccessibleWrap : public XULTreeGridAccessible,
                                   public ia2AccessibleTable
 {
 public:
-  XULTreeGridAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc);
+  XULTreeGridAccessibleWrap(nsIContent* aContent, DocAccessible* aDoc) :
+    XULTreeGridAccessible(aContent, aDoc), ia2AccessibleTable(this) {}
 
   // IUnknown
   DECL_IUNKNOWN_INHERITED
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
+
+  virtual void Shutdown() MOZ_OVERRIDE;
 };
 
 /**
diff --git a/accessible/src/windows/ia2/ia2AccessibleTable.cpp b/accessible/src/windows/ia2/ia2AccessibleTable.cpp
index a8fc92b44e26..fe196e8e8e41 100644
--- a/accessible/src/windows/ia2/ia2AccessibleTable.cpp
+++ b/accessible/src/windows/ia2/ia2AccessibleTable.cpp
@@ -11,21 +11,15 @@
 #include "AccessibleTable_i.c"
 #include "AccessibleTable2_i.c"
 
-#include "nsIAccessible.h"
-#include "nsIAccessibleTable.h"
-#include "nsIWinAccessNode.h"
-#include "nsAccessNodeWrap.h"
-#include "nsWinUtils.h"
+#include "AccessibleWrap.h"
 #include "Statistics.h"
+#include "TableAccessible.h"
 
 #include "nsCOMPtr.h"
 #include "nsString.h"
 
 using namespace mozilla::a11y;
 
-#define CANT_QUERY_ASSERTION_MSG \
-"Subclass of ia2AccessibleTable doesn't implement nsIAccessibleTable"\
-
 // IUnknown
 
 STDMETHODIMP
@@ -53,36 +47,10 @@ ia2AccessibleTable::QueryInterface(REFIID iid, void** ppv)
 // IAccessibleTable
 
 STDMETHODIMP
-ia2AccessibleTable::get_accessibleAt(long aRow, long aColumn,
-                                   IUnknown **aAccessible)
+ia2AccessibleTable::get_accessibleAt(long aRowIdx, long aColIdx,
+                                     IUnknown** aAccessible)
 {
-  A11Y_TRYBLOCK_BEGIN
-
-  *aAccessible = NULL;
-
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  nsCOMPtr<nsIAccessible> cell;
-  nsresult rv = tableAcc->GetCellAt(aRow, aColumn, getter_AddRefs(cell));
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  nsCOMPtr<nsIWinAccessNode> winAccessNode(do_QueryInterface(cell));
-  if (!winAccessNode)
-    return E_FAIL;
-
-  void *instancePtr = NULL;
-  rv = winAccessNode->QueryNativeInterface(IID_IAccessible2, &instancePtr);
-  if (NS_FAILED(rv))
-    return E_FAIL;
-
-  *aAccessible = static_cast<IUnknown*>(instancePtr);
-  return S_OK;
-
-  A11Y_TRYBLOCK_END
+  return get_cellAt(aRowIdx, aColIdx, aAccessible);
 }
 
 STDMETHODIMP
@@ -91,76 +59,54 @@ ia2AccessibleTable::get_caption(IUnknown** aAccessible)
   A11Y_TRYBLOCK_BEGIN
 
   *aAccessible = NULL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  nsCOMPtr<nsIAccessible> caption;
-  nsresult rv = tableAcc->GetCaption(getter_AddRefs(caption));
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
+  AccessibleWrap* caption = static_cast<AccessibleWrap*>(mTable->Caption());
   if (!caption)
     return S_FALSE;
 
-  nsCOMPtr<nsIWinAccessNode> winAccessNode(do_QueryInterface(caption));
-  if (!winAccessNode)
-    return E_FAIL;
-
-  void *instancePtr = NULL;
-  rv = winAccessNode->QueryNativeInterface(IID_IAccessible2, &instancePtr);
-  if (NS_FAILED(rv))
-    return E_FAIL;
-
-  *aAccessible = static_cast<IUnknown*>(instancePtr);
+  (*aAccessible = static_cast<IAccessible*>(caption))->AddRef();
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_childIndex(long aRowIndex, long aColumnIndex,
-                                   long* aChildIndex)
+ia2AccessibleTable::get_childIndex(long aRowIdx, long aColIdx,
+                                   long* aChildIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aChildIndex = 0;
+  *aChildIdx = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aRowIdx < 0 || aColIdx < 0 ||
+      static_cast<uint32_t>(aRowIdx) >= mTable->RowCount() ||
+      static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
 
-  int32_t childIndex = 0;
-  nsresult rv = tableAcc->GetCellIndexAt(aRowIndex, aColumnIndex, &childIndex);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aChildIndex = childIndex;
+  *aChildIdx = mTable->CellIndexAt(aRowIdx, aColIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_columnDescription(long aColumn, BSTR* aDescription)
+ia2AccessibleTable::get_columnDescription(long aColIdx, BSTR* aDescription)
 {
   A11Y_TRYBLOCK_BEGIN
 
   *aDescription = NULL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aColIdx < 0 || static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
 
   nsAutoString descr;
-  nsresult rv = tableAcc->GetColumnDescription (aColumn, descr);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
+  mTable->ColDescription(aColIdx, descr);
   if (descr.IsEmpty())
     return S_FALSE;
 
@@ -171,24 +117,21 @@ ia2AccessibleTable::get_columnDescription(long aColumn, BSTR* aDescription)
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_columnExtentAt(long aRow, long aColumn,
-                                      long* nColumnsSpanned)
+ia2AccessibleTable::get_columnExtentAt(long aRowIdx, long aColIdx,
+                                      long* aSpan)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *nColumnsSpanned = 0;
+  *aSpan = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aRowIdx < 0 || aColIdx < 0 ||
+      static_cast<uint32_t>(aRowIdx) >= mTable->RowCount() ||
+      static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
 
-  int32_t columnsSpanned = 0;
-  nsresult rv = tableAcc->GetColumnExtentAt(aRow, aColumn, &columnsSpanned);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *nColumnsSpanned = columnsSpanned;
+  *aSpan = mTable->ColExtentAt(aRowIdx, aColIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -208,46 +151,34 @@ ia2AccessibleTable::get_columnHeader(IAccessibleTable** aAccessibleTable,
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_columnIndex(long aChildIndex, long* aColumnIndex)
+ia2AccessibleTable::get_columnIndex(long aCellIdx, long* aColIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aColumnIndex = 0;
+  *aColIdx = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aCellIdx < 0 ||
+      static_cast<uint32_t>(aCellIdx) >= mTable->ColCount() * mTable->RowCount())
+    return E_INVALIDARG;
 
-  int32_t columnIndex = 0;
-  nsresult rv = tableAcc->GetColumnIndexAt(aChildIndex, &columnIndex);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aColumnIndex = columnIndex;
+  *aColIdx = mTable->ColIndexAt(aCellIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_nColumns(long* aColumnCount)
+ia2AccessibleTable::get_nColumns(long* aColCount)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aColumnCount = 0;
+  *aColCount = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  int32_t columnCount = 0;
-  nsresult rv = tableAcc->GetColumnCount(&columnCount);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aColumnCount = columnCount;
+  *aColCount = mTable->ColCount();
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -259,18 +190,10 @@ ia2AccessibleTable::get_nRows(long* aRowCount)
   A11Y_TRYBLOCK_BEGIN
 
   *aRowCount = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  int32_t rowCount = 0;
-  nsresult rv = tableAcc->GetRowCount(&rowCount);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aRowCount = rowCount;
+  *aRowCount = mTable->RowCount();
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -279,44 +202,19 @@ ia2AccessibleTable::get_nRows(long* aRowCount)
 STDMETHODIMP
 ia2AccessibleTable::get_nSelectedChildren(long* aChildCount)
 {
-  A11Y_TRYBLOCK_BEGIN
-
-  *aChildCount = 0;
-
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  uint32_t count = 0;
-  nsresult rv = tableAcc->GetSelectedCellCount(&count);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aChildCount = count;
-  return S_OK;
-
-  A11Y_TRYBLOCK_END
+  return get_nSelectedCells(aChildCount);
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_nSelectedColumns(long* aColumnCount)
+ia2AccessibleTable::get_nSelectedColumns(long* aColCount)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aColumnCount = 0;
+  *aColCount = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  uint32_t count = 0;
-  nsresult rv = tableAcc->GetSelectedColumnCount(&count);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aColumnCount = count;
+  *aColCount = mTable->SelectedColCount();
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -328,40 +226,30 @@ ia2AccessibleTable::get_nSelectedRows(long* aRowCount)
   A11Y_TRYBLOCK_BEGIN
 
   *aRowCount = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  *aRowCount = mTable->SelectedRowCount();
 
-  uint32_t count = 0;
-  nsresult rv = tableAcc->GetSelectedRowCount(&count);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aRowCount = count;
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_rowDescription(long aRow, BSTR* aDescription)
+ia2AccessibleTable::get_rowDescription(long aRowIdx, BSTR* aDescription)
 {
   A11Y_TRYBLOCK_BEGIN
 
   *aDescription = NULL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aRowIdx < 0 || static_cast<uint32_t>(aRowIdx) >= mTable->RowCount())
+    return E_INVALIDARG;
 
   nsAutoString descr;
-  nsresult rv = tableAcc->GetRowDescription (aRow, descr);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
+  mTable->RowDescription(aRowIdx, descr);
   if (descr.IsEmpty())
     return S_FALSE;
 
@@ -372,24 +260,20 @@ ia2AccessibleTable::get_rowDescription(long aRow, BSTR* aDescription)
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_rowExtentAt(long aRow, long aColumn,
-                                    long* aNRowsSpanned)
+ia2AccessibleTable::get_rowExtentAt(long aRowIdx, long aColIdx, long* aSpan)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aNRowsSpanned = 0;
+  *aSpan = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aRowIdx < 0 || aColIdx < 0 ||
+      static_cast<uint32_t>(aRowIdx) >= mTable->RowCount() ||
+      static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
 
-  int32_t rowsSpanned = 0;
-  nsresult rv = tableAcc->GetRowExtentAt(aRow, aColumn, &rowsSpanned);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aNRowsSpanned = rowsSpanned;
+  *aSpan = mTable->RowExtentAt(aRowIdx, aColIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -409,23 +293,19 @@ ia2AccessibleTable::get_rowHeader(IAccessibleTable** aAccessibleTable,
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_rowIndex(long aChildIndex, long* aRowIndex)
+ia2AccessibleTable::get_rowIndex(long aCellIdx, long* aRowIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aRowIndex = 0;
+  *aRowIdx = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aCellIdx < 0 ||
+      static_cast<uint32_t>(aCellIdx) >= mTable->ColCount() * mTable->RowCount())
+    return E_INVALIDARG;
 
-  int32_t rowIndex = 0;
-  nsresult rv = tableAcc->GetRowIndexAt(aChildIndex, &rowIndex);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aRowIndex = rowIndex;
+  *aRowIdx = mTable->RowIndexAt(aCellIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -437,7 +317,24 @@ ia2AccessibleTable::get_selectedChildren(long aMaxChildren, long** aChildren,
 {
   A11Y_TRYBLOCK_BEGIN
 
-  return GetSelectedItems(aChildren, aNChildren, ITEMSTYPE_CELLS);
+  *aChildren = NULL;
+  *aNChildren = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
+
+  nsAutoTArray<uint32_t, 30> cellIndices;
+  mTable->SelectedCellIndices(&cellIndices);
+
+  uint32_t maxCells = cellIndices.Length();
+  if (maxCells == 0)
+    return S_FALSE;
+
+  *aChildren = static_cast<LONG*>(moz_xmalloc(sizeof(LONG) * maxCells));
+  *aNChildren = maxCells;
+  for (uint32_t i = 0; i < maxCells; i++)
+    (*aChildren)[i] = cellIndices[i];
+
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
@@ -448,7 +345,7 @@ ia2AccessibleTable::get_selectedColumns(long aMaxColumns, long** aColumns,
 {
   A11Y_TRYBLOCK_BEGIN
 
-  return GetSelectedItems(aColumns, aNColumns, ITEMSTYPE_COLUMNS);
+  return get_selectedColumns(aColumns, aNColumns);
 
   A11Y_TRYBLOCK_END
 }
@@ -458,7 +355,7 @@ ia2AccessibleTable::get_selectedRows(long aMaxRows, long** aRows, long* aNRows)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  return GetSelectedItems(aRows, aNRows, ITEMSTYPE_ROWS);
+  return get_selectedRows(aRows, aNRows);
 
   A11Y_TRYBLOCK_END
 }
@@ -480,182 +377,159 @@ ia2AccessibleTable::get_summary(IUnknown** aAccessible)
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_isColumnSelected(long aColumn, boolean* aIsSelected)
+ia2AccessibleTable::get_isColumnSelected(long aColIdx, boolean* aIsSelected)
 {
   A11Y_TRYBLOCK_BEGIN
 
   *aIsSelected = false;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aColIdx < 0 || static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
 
-  bool isSelected = false;
-  nsresult rv = tableAcc->IsColumnSelected(aColumn, &isSelected);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aIsSelected = isSelected;
+  *aIsSelected = mTable->IsColSelected(aColIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_isRowSelected(long aRow, boolean* aIsSelected)
+ia2AccessibleTable::get_isRowSelected(long aRowIdx, boolean* aIsSelected)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  *aIsSelected = false;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  bool isSelected = false;
-  nsresult rv = tableAcc->IsRowSelected(aRow, &isSelected);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
+  if (aRowIdx < 0 || static_cast<uint32_t>(aRowIdx) >= mTable->RowCount())
+    return E_INVALIDARG;
 
-  *aIsSelected = isSelected;
+  *aIsSelected = mTable->IsRowSelected(aRowIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_isSelected(long aRow, long aColumn,
+ia2AccessibleTable::get_isSelected(long aRowIdx, long aColIdx,
                                    boolean* aIsSelected)
 {
   A11Y_TRYBLOCK_BEGIN
 
   *aIsSelected = false;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aRowIdx < 0 || aColIdx < 0 ||
+      static_cast<uint32_t>(aColIdx) >= mTable->ColCount() ||
+      static_cast<uint32_t>(aRowIdx) >= mTable->RowCount())
+    return E_INVALIDARG;
 
-  bool isSelected = false;
-  nsresult rv = tableAcc->IsCellSelected(aRow, aColumn, &isSelected);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aIsSelected = isSelected;
+  *aIsSelected = mTable->IsCellSelected(aRowIdx, aColIdx);
   return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::selectRow(long aRow)
+ia2AccessibleTable::selectRow(long aRowIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsresult rv = tableAcc->SelectRow(aRow);
-  return GetHRESULT(rv);
+  if (aRowIdx < 0 || static_cast<uint32_t>(aRowIdx) >= mTable->RowCount())
+    return E_INVALIDARG;
+
+  mTable->SelectRow(aRowIdx);
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::selectColumn(long aColumn)
+ia2AccessibleTable::selectColumn(long aColIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsresult rv = tableAcc->SelectColumn(aColumn);
-  return GetHRESULT(rv);
+  if (aColIdx < 0 || static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
+
+  mTable->SelectCol(aColIdx);
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::unselectRow(long aRow)
+ia2AccessibleTable::unselectRow(long aRowIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsresult rv = tableAcc->UnselectRow(aRow);
-  return GetHRESULT(rv);
+  if (aRowIdx < 0 || static_cast<uint32_t>(aRowIdx) >= mTable->RowCount())
+    return E_INVALIDARG;
+
+  mTable->UnselectRow(aRowIdx);
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::unselectColumn(long aColumn)
+ia2AccessibleTable::unselectColumn(long aColIdx)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsresult rv = tableAcc->UnselectColumn(aColumn);
-  return GetHRESULT(rv);
+  if (aColIdx < 0 || static_cast<uint32_t>(aColIdx) >= mTable->ColCount())
+    return E_INVALIDARG;
+
+  mTable->UnselectCol(aColIdx);
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
-ia2AccessibleTable::get_rowColumnExtentsAtIndex(long aIndex, long* aRow,
-                                                long* aColumn,
+ia2AccessibleTable::get_rowColumnExtentsAtIndex(long aCellIdx, long* aRowIdx,
+                                                long* aColIdx,
                                                 long* aRowExtents,
-                                                long* aColumnExtents,
+                                                long* aColExtents,
                                                 boolean* aIsSelected)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  *aRow = 0;
-  *aColumn = 0;
+  *aRowIdx = 0;
+  *aColIdx = 0;
   *aRowExtents = 0;
-  *aColumnExtents = 0;
+  *aColExtents = 0;
   *aIsSelected = false;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  if (aCellIdx < 0 ||
+      static_cast<uint32_t>(aCellIdx) >= mTable->ColCount() * mTable->RowCount())
+    return E_INVALIDARG;
 
-  int32_t rowIdx = -1, columnIdx = -1;
-  nsresult rv = tableAcc->GetRowAndColumnIndicesAt(aIndex, &rowIdx, &columnIdx);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
+  int32_t colIdx = 0, rowIdx = 0;
+  mTable->RowAndColIndicesAt(aCellIdx, &rowIdx, &colIdx);
+  *aRowIdx = rowIdx;
+  *aColIdx = colIdx;
+  *aRowExtents = mTable->RowExtentAt(rowIdx, colIdx);
+  *aColExtents = mTable->ColExtentAt(rowIdx, colIdx);
+  *aIsSelected = mTable->IsCellSelected(rowIdx, colIdx);
 
-  int32_t rowExtents = 0;
-  rv = tableAcc->GetRowExtentAt(rowIdx, columnIdx, &rowExtents);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  int32_t columnExtents = 0;
-  rv = tableAcc->GetColumnExtentAt(rowIdx, columnIdx, &columnExtents);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  bool isSelected = false;
-  rv = tableAcc->IsCellSelected(rowIdx, columnIdx, &isSelected);
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  *aRow = rowIdx;
-  *aColumn = columnIdx;
-  *aRowExtents = rowExtents;
-  *aColumnExtents = columnExtents;
-  *aIsSelected = isSelected;
   return S_OK;
 
   A11Y_TRYBLOCK_END
@@ -671,15 +545,39 @@ ia2AccessibleTable::get_modelChange(IA2TableModelChange* aModelChange)
 // IAccessibleTable2
 
 STDMETHODIMP
-ia2AccessibleTable::get_cellAt(long aRow, long aColumn, IUnknown** aCell)
+ia2AccessibleTable::get_cellAt(long aRowIdx, long aColIdx, IUnknown** aCell)
 {
-  return get_accessibleAt(aRow, aColumn, aCell);
+  A11Y_TRYBLOCK_BEGIN
+
+  *aCell = NULL;
+
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
+
+  AccessibleWrap* cell =
+    static_cast<AccessibleWrap*>(mTable->CellAt(aRowIdx, aColIdx));
+  if (!cell)
+    return E_INVALIDARG;
+
+  (*aCell = static_cast<IAccessible*>(cell))->AddRef();
+  return S_OK;
+
+  A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
 ia2AccessibleTable::get_nSelectedCells(long* aCellCount)
 {
-  return get_nSelectedChildren(aCellCount);
+  A11Y_TRYBLOCK_BEGIN
+
+  *aCellCount = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
+
+  *aCellCount = mTable->SelectedCellCount();
+  return S_OK;
+
+  A11Y_TRYBLOCK_END
 }
 
 STDMETHODIMP
@@ -687,17 +585,30 @@ ia2AccessibleTable::get_selectedCells(IUnknown*** aCells, long* aNSelectedCells)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
+  *aCells = NULL;
+  *aNSelectedCells = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
 
-  nsCOMPtr<nsIArray> geckoCells;
-  nsresult rv = tableAcc->GetSelectedCells(getter_AddRefs(geckoCells));
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
+  nsAutoTArray<Accessible*, 30> cells;
+  mTable->SelectedCells(&cells);
+  if (cells.IsEmpty())
+    return S_FALSE;
 
-  return nsWinUtils::ConvertToIA2Array(geckoCells, aCells, aNSelectedCells);
+  *aCells =
+    static_cast<IUnknown**>(::CoTaskMemAlloc(sizeof(IUnknown*) *
+                                             cells.Length()));
+  if (!*aCells)
+    return E_OUTOFMEMORY;
+
+  for (uint32_t i = 0; i < cells.Length(); i++) {
+    (*aCells)[i] =
+      static_cast<IAccessible*>(static_cast<AccessibleWrap*>(cells[i]));
+    ((*aCells)[i])->AddRef();
+  }
+
+  *aNSelectedCells = cells.Length();
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
@@ -707,7 +618,24 @@ ia2AccessibleTable::get_selectedColumns(long** aColumns, long* aNColumns)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  return GetSelectedItems(aColumns, aNColumns, ITEMSTYPE_COLUMNS);
+  *aColumns = NULL;
+  *aNColumns = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
+
+  nsAutoTArray<uint32_t, 30> colIndices;
+  mTable->SelectedColIndices(&colIndices);
+
+  uint32_t maxCols = colIndices.Length();
+  if (maxCols == 0)
+    return S_FALSE;
+
+  *aColumns = static_cast<LONG*>(moz_xmalloc(sizeof(LONG) * maxCols));
+  *aNColumns = maxCols;
+  for (uint32_t i = 0; i < maxCols; i++)
+    (*aColumns)[i] = colIndices[i];
+
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
@@ -717,58 +645,24 @@ ia2AccessibleTable::get_selectedRows(long** aRows, long* aNRows)
 {
   A11Y_TRYBLOCK_BEGIN
 
-  return GetSelectedItems(aRows, aNRows, ITEMSTYPE_ROWS);
+  *aRows = NULL;
+  *aNRows = 0;
+  if (!mTable)
+    return CO_E_OBJNOTCONNECTED;
+
+  nsAutoTArray<uint32_t, 30> rowIndices;
+  mTable->SelectedRowIndices(&rowIndices);
+
+  uint32_t maxRows = rowIndices.Length();
+  if (maxRows == 0)
+    return S_FALSE;
+
+  *aRows = static_cast<LONG*>(moz_xmalloc(sizeof(LONG) * maxRows));
+  *aNRows = maxRows;
+  for (uint32_t i = 0; i < maxRows; i++)
+    (*aRows)[i] = rowIndices[i];
+
+  return S_OK;
 
   A11Y_TRYBLOCK_END
 }
-
-////////////////////////////////////////////////////////////////////////////////
-// ia2AccessibleTable public
-
-HRESULT
-ia2AccessibleTable::GetSelectedItems(long** aItems, long* aItemsCount,
-                                     eItemsType aType)
-{
-  *aItemsCount = 0;
-
-  nsCOMPtr<nsIAccessibleTable> tableAcc(do_QueryObject(this));
-  NS_ASSERTION(tableAcc, CANT_QUERY_ASSERTION_MSG);
-  if (!tableAcc)
-    return E_FAIL;
-
-  uint32_t size = 0;
-  int32_t *items = nullptr;
-
-  nsresult rv = NS_OK;
-  switch (aType) {
-    case ITEMSTYPE_CELLS:
-      rv = tableAcc->GetSelectedCellIndices(&size, &items);
-      break;
-    case ITEMSTYPE_COLUMNS:
-      rv = tableAcc->GetSelectedColumnIndices(&size, &items);
-      break;
-    case ITEMSTYPE_ROWS:
-      rv = tableAcc->GetSelectedRowIndices(&size, &items);
-      break;
-    default:
-      return E_FAIL;
-  }
-
-  if (NS_FAILED(rv))
-    return GetHRESULT(rv);
-
-  if (size == 0 || !items)
-    return S_FALSE;
-
-  *aItems = static_cast<long*>(nsMemory::Alloc((size) * sizeof(long)));
-  if (!*aItems)
-    return E_OUTOFMEMORY;
-
-  *aItemsCount = size;
-  for (uint32_t index = 0; index < size; ++index)
-    (*aItems)[index] = items[index];
-
-  nsMemory::Free(items);
-  return S_OK;
-}
-
diff --git a/accessible/src/windows/ia2/ia2AccessibleTable.h b/accessible/src/windows/ia2/ia2AccessibleTable.h
index 73470bcba6ee..6738e2dfc2df 100644
--- a/accessible/src/windows/ia2/ia2AccessibleTable.h
+++ b/accessible/src/windows/ia2/ia2AccessibleTable.h
@@ -8,11 +8,14 @@
 #ifndef _ACCESSIBLE_TABLE_H
 #define _ACCESSIBLE_TABLE_H
 
-#include "nsISupports.h"
-
 #include "AccessibleTable.h"
 #include "AccessibleTable2.h"
 
+namespace mozilla {
+namespace a11y {
+
+class TableAccessible;
+
 class ia2AccessibleTable : public IAccessibleTable,
                            public IAccessibleTable2
 {
@@ -161,17 +164,13 @@ public:
       /* [out, size_is(,*nRows)] */ long **selectedRows, 
       /* [out, retval] */ long *nRows);
 
-  // nsISupports
-  NS_IMETHOD QueryInterface(const nsIID& uuid, void** result) = 0;
+protected:
+  ia2AccessibleTable(TableAccessible* aTable) : mTable(aTable) {}
 
-private:
-  enum eItemsType {
-    ITEMSTYPE_CELLS,
-    ITEMSTYPE_COLUMNS,
-    ITEMSTYPE_ROWS
-  };
-
-  HRESULT GetSelectedItems(long **aItems, long *aItemsCount, eItemsType aType);
+  TableAccessible* mTable;
 };
 
+} // namespace a11y
+} // namespace mozilla
+
 #endif