C++11: Replace 0 with nullptr where applicable in layout code.

Source/core/layout/LayoutTableCell.cpp

 /*
  * 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, 2008, 2009 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
@@ skipping 683 matching lines @@
             return result;
     }
 
     // (3) Our row's before border.
     result = chooseBorder(result, CollapsedBorderValue(parent()->style()->borderBefore(), includeColor ? parent()->resolveColor(beforeColorProperty) : Color(), BROW));
     if (!result.exists())
         return result;
 
     // (4) The previous row's after border.
     if (prevCell) {
-        LayoutObject* prevRow = 0;
+        LayoutObject* prevRow = nullptr;
         if (prevCell->section() == section())
             prevRow = parent()->previousSibling();
         else
             prevRow = prevCell->section()->lastRow();
 
         if (prevRow) {
             result = chooseBorder(CollapsedBorderValue(prevRow->style()->borderAfter(), includeColor ? prevRow->resolveColor(afterColorProperty) : Color(), BROW), result);
             if (!result.exists())
                 return result;
         }
@@ skipping 306 matching lines @@
         LayoutUnit newAfterPadding = totalHeight - heightWithoutIntrinsicPadding - newBeforePadding;
         setIntrinsicPaddingBefore(newBeforePadding);
         setIntrinsicPaddingAfter(newAfterPadding);
     } else {
         setIntrinsicPaddingAfter(intrinsicPaddingAfter() - scrollbarHeight);
     }
 }
 
 LayoutTableCell* LayoutTableCell::createAnonymous(Document* document)
 {
-    LayoutTableCell* layoutObject = new LayoutTableCell(0);
+    LayoutTableCell* layoutObject = new LayoutTableCell(nullptr);
     layoutObject->setDocumentForAnonymous(document);
     return layoutObject;
 }
 
 LayoutTableCell* LayoutTableCell::createAnonymousWithParent(const LayoutObject* parent)
 {
     LayoutTableCell* newCell = LayoutTableCell::createAnonymous(&parent->document());
     RefPtr<ComputedStyle> newStyle = ComputedStyle::createAnonymousStyleWithDisplay(parent->styleRef(), TABLE_CELL);
     newCell->setStyle(newStyle.release());
     return newCell;
 }
 
 } // namespace blink