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

Source/core/layout/LayoutTableRow.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, 2010, 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
@@ skipping 209 matching lines @@
 }
 
 void LayoutTableRow::imageChanged(WrappedImagePtr, const IntRect*)
 {
     // FIXME: Examine cells and issue paint invalidations of only the rect the image paints in.
     setShouldDoFullPaintInvalidation();
 }
 
 LayoutTableRow* LayoutTableRow::createAnonymous(Document* document)
 {
-    LayoutTableRow* layoutObject = new LayoutTableRow(0);
+    LayoutTableRow* layoutObject = new LayoutTableRow(nullptr);
     layoutObject->setDocumentForAnonymous(document);
     return layoutObject;
 }
 
 LayoutTableRow* LayoutTableRow::createAnonymousWithParent(const LayoutObject* parent)
 {
     LayoutTableRow* newRow = LayoutTableRow::createAnonymous(&parent->document());
     RefPtr<ComputedStyle> newStyle = ComputedStyle::createAnonymousStyleWithDisplay(parent->styleRef(), TABLE_ROW);
     newRow->setStyle(newStyle.release());
     return newRow;
@@ skipping 11 matching lines @@
     // The cell and the row share the section's coordinate system. However
     // the visual overflow should be determined in the coordinate system of
     // the row, that's why we shift it below.
     LayoutUnit cellOffsetLogicalTopDifference = cell->location().y() - location().y();
     cellVisualOverflowRect.move(0, cellOffsetLogicalTopDifference);
 
     addVisualOverflow(cellVisualOverflowRect);
 }
 
 } // namespace blink