GridPainter::paintChild should take RenderBox reference

Source/core/paint/GridPainter.cpp

 // 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.
 
 #include "config.h"
 #include "core/paint/GridPainter.h"
 
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderGrid.h"
 
@@ skipping 56 matching lines @@
     std::stable_sort(gridItemsToBePainted.begin(), gridItemsToBePainted.end(), GridItemsSorter());
 
     RenderBox* previous = 0;
     for (Vector<std::pair<RenderBox*, size_t> >::const_iterator it = gridItemsToBePainted.begin(); it != gridItemsToBePainted.end(); ++it) {
         // We might have duplicates because of spanning children are included in all cells they span.
         // Skip them here to avoid painting items several times.
         RenderBox* current = it->first;
         if (current == previous)
             continue;
 
-        paintChild(current, paintInfo, paintOffset);
+        paintChild(*current, paintInfo, paintOffset);
         previous = current;
     }
 }
 
-void GridPainter::paintChild(RenderBox* child, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+void GridPainter::paintChild(RenderBox& child, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
-    LayoutPoint childPoint = m_renderGrid.flipForWritingModeForChild(child, paintOffset);
-    if (!child->hasSelfPaintingLayer() && !child->isFloating())
-        child->paint(paintInfo, childPoint);
+    LayoutPoint childPoint = m_renderGrid.flipForWritingModeForChild(&child, paintOffset);
+    if (!child.hasSelfPaintingLayer() && !child.isFloating())
+        child.paint(paintInfo, childPoint);
 }
 
 } // namespace blink