Use tighter typing in table rendering code

Source/core/rendering/RenderTableCell.h

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
- * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
@@ skipping 52 matching lines @@
     unsigned col() const
     {
         ASSERT(m_column != unsetColumnIndex);
         return m_column;
     }
 
     RenderTableRow* row() const { return toRenderTableRow(parent()); }
     RenderTableSection* section() const { return toRenderTableSection(parent()->parent()); }
     RenderTable* table() const { return toRenderTable(parent()->parent()->parent()); }
 
+    RenderTableCell* previousCell() const;
+    RenderTableCell* nextCell() const;
+
     unsigned rowIndex() const
     {
         // This function shouldn't be called on a detached cell.
         ASSERT(row());
         return row()->rowIndex();
     }
 
     Length styleOrColLogicalWidth() const
     {
         Length styleWidth = style()->logicalWidth();
@@ skipping 180 matching lines @@
     CollapsedBorderValue computeCollapsedBeforeBorder(IncludeBorderColorOrNot = IncludeBorderColor) const;
     CollapsedBorderValue computeCollapsedAfterBorder(IncludeBorderColorOrNot = IncludeBorderColor) const;
 
     Length logicalWidthFromColumns(RenderTableCol* firstColForThisCell, Length widthFromStyle) const;
 
     void updateColAndRowSpanFlags();
 
     unsigned parseRowSpanFromDOM() const;
     unsigned parseColSpanFromDOM() const;
 
+    void nextSibling() const WTF_DELETED_FUNCTION;
+    void previousSibling() const WTF_DELETED_FUNCTION;
+
     // Note MSVC will only pack members if they have identical types, hence we use unsigned instead of bool here.
     unsigned m_column : 29;
     unsigned m_cellWidthChanged : 1;
     unsigned m_hasColSpan: 1;
     unsigned m_hasRowSpan: 1;
     int m_intrinsicPaddingBefore;
     int m_intrinsicPaddingAfter;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderTableCell, isTableCell());
 
+inline RenderTableCell* RenderTableCell::previousCell() const
+{
+    return toRenderTableCell(RenderObject::previousSibling());
+}
+
+inline RenderTableCell* RenderTableCell::nextCell() const
+{
+    return toRenderTableCell(RenderObject::nextSibling());
+}
+
+inline RenderTableCell* RenderTableRow::firstCell() const
+{
+    ASSERT(children() == virtualChildren());
+    return toRenderTableCell(children()->firstChild());
+}
+
+inline RenderTableCell* RenderTableRow::lastCell() const
+{
+    ASSERT(children() == virtualChildren());
+    return toRenderTableCell(children()->lastChild());
+}
+
 } // namespace WebCore
 
 #endif // RenderTableCell_h