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

Source/core/layout/TableLayoutAlgorithmAuto.cpp

 /*
  * Copyright (C) 2002 Lars Knoll (knoll@kde.org)
  *           (C) 2002 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2008, 2010 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License.
  *
@@ skipping 27 matching lines @@
 }
 
 TableLayoutAlgorithmAuto::~TableLayoutAlgorithmAuto()
 {
 }
 
 void TableLayoutAlgorithmAuto::recalcColumn(unsigned effCol)
 {
     Layout& columnLayout = m_layoutStruct[effCol];
 
-    LayoutTableCell* fixedContributor = 0;
-    LayoutTableCell* maxContributor = 0;
+    LayoutTableCell* fixedContributor = nullptr;
+    LayoutTableCell* maxContributor = nullptr;
 
     for (LayoutObject* child = m_table->children()->firstChild(); child; child = child->nextSibling()) {
         if (child->isLayoutTableCol()) {
             // LayoutTableCols don't have the concept of preferred logical width, but we need to clear their dirty bits
             // so that if we call setPreferredWidthsDirty(true) on a col or one of its descendants, we'll mark it's
             // ancestors as dirty.
             toLayoutTableCol(child)->clearPreferredLogicalWidthsDirtyBits();
         } else if (child->isTableSection()) {
             LayoutTableSection* section = toLayoutTableSection(child);
             unsigned numRows = section->numRows();
@@ skipping 64 matching lines @@
                     insertSpanCell(cell);
                 }
             }
         }
     }
 
     // Nav/IE weirdness
     if (columnLayout.logicalWidth.isFixed()) {
         if (m_table->document().inQuirksMode() && columnLayout.maxLogicalWidth > columnLayout.logicalWidth.value() && fixedContributor != maxContributor) {
             columnLayout.logicalWidth = Length();
-            fixedContributor = 0;
+            fixedContributor = nullptr;
         }
     }
 
     columnLayout.maxLogicalWidth = std::max(columnLayout.maxLogicalWidth, columnLayout.minLogicalWidth);
 }
 
 void TableLayoutAlgorithmAuto::fullRecalc()
 {
     m_hasPercent = false;
     m_effectiveLogicalWidthDirty = true;
@@ skipping 547 matching lines @@
             int reduce = available * minMaxDiff / logicalWidthBeyondMin;
             m_layoutStruct[i].computedLogicalWidth += reduce;
             available -= reduce;
             logicalWidthBeyondMin -= minMaxDiff;
             if (available >= 0)
                 break;
         }
     }
 }
 }