Move painting code from RenderTableCell to TableCellPainter.

Source/core/paint/TableCellPainter.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TableCellPainter_h
+#define TableCellPainter_h
+
+#include "core/rendering/style/CollapsedBorderValue.h"
+
+namespace blink {
+
+struct PaintInfo;
+class LayoutPoint;
+class RenderObject;
+class RenderStyle;
+class RenderTableCell;
+
+class TableCellPainter {
+public:
+    TableCellPainter(RenderTableCell& renderTableCell) : m_renderTableCell(renderTableCell) { }
+
+    void paint(PaintInfo&, const LayoutPoint&);
+
+    void paintCollapsedBorders(PaintInfo&, const LayoutPoint&);
+    void paintBackgroundsBehindCell(PaintInfo&, const LayoutPoint&, RenderObject* backgroundObject);
+    void paintBoxDecorationBackground(PaintInfo&, const LayoutPoint& paintOffset);
+    void paintMask(PaintInfo&, const LayoutPoint& paintOffset);
+
+private:
+    CollapsedBorderValue cachedCollapsedLeftBorder(const RenderStyle*) const;
+    CollapsedBorderValue cachedCollapsedRightBorder(const RenderStyle*) const;
+    CollapsedBorderValue cachedCollapsedTopBorder(const RenderStyle*) const;
+    CollapsedBorderValue cachedCollapsedBottomBorder(const RenderStyle*) const;
+
+    RenderTableCell& m_renderTableCell;
+};
+
+} // namespace blink
+
+#endif // TableCellPainter_h