Make LayoutState always be RAII

Source/core/rendering/RenderTable.h

Index: Source/core/rendering/RenderTable.h
diff --git a/Source/core/rendering/RenderTable.h b/Source/core/rendering/RenderTable.h
index 9c460df3735c95312d3bb643d589df882166a65e..f20b9e84685deb0da41a7513e57400fc4e2446e8 100644
--- a/Source/core/rendering/RenderTable.h
+++ b/Source/core/rendering/RenderTable.h
@@ -36,6 +36,7 @@ class RenderTableCol;
 class RenderTableCaption;
 class RenderTableCell;
 class RenderTableSection;
+class SubtreeLayoutScope;
 class TableLayout;
 
 enum SkipEmptySectionsValue { DoNotSkipEmptySections, SkipEmptySections };
@@ -284,6 +285,7 @@ private:
     virtual void paintBoxDecorations(PaintInfo&, const LayoutPoint&) OVERRIDE;
     virtual void paintMask(PaintInfo&, const LayoutPoint&) OVERRIDE;
     virtual void layout() OVERRIDE;
+    void layoutContents(SubtreeLayoutScope&, bool& sectionMoved, LayoutUnit& movedSectionLogicalTop);
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minWidth, LayoutUnit& maxWidth) const OVERRIDE;
     virtual void computePreferredLogicalWidths() OVERRIDE;