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

Source/core/layout/TextAutosizer.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 130 matching lines @@
             , m_multiplier(0)
         {
         }
 
         const BlockSet* const m_roots;
         HasEnoughTextToAutosize m_hasEnoughTextToAutosize;
         float m_multiplier;
     };
 
     struct Cluster {
-        explicit Cluster(const LayoutBlock* root, BlockFlags flags, Cluster* parent, Supercluster* supercluster = 0)
+        explicit Cluster(const LayoutBlock* root, BlockFlags flags, Cluster* parent, Supercluster* supercluster = nullptr)
             : m_root(root)
             , m_flags(flags)
-            , m_deepestBlockContainingAllText(0)
+            , m_deepestBlockContainingAllText(nullptr)
             , m_parent(parent)
             , m_multiplier(0)
             , m_hasEnoughTextToAutosize(UnknownAmountOfText)
             , m_supercluster(supercluster)
             , m_hasTableAncestor(root->isTableCell() || (m_parent && m_parent->m_hasTableAncestor))
         {
         }
 
         const LayoutBlock* const m_root;
         BlockFlags m_flags;
@@ skipping 88 matching lines @@
     void beginLayout(LayoutBlock*);
     void endLayout(LayoutBlock*);
     void inflateAutoTable(LayoutTable*);
     float inflate(LayoutObject*, InflateBehavior = ThisBlockOnly, float multiplier = 0);
     bool shouldHandleLayout() const;
     IntSize windowSize() const;
     void setAllTextNeedsLayout();
     void resetMultipliers();
     BeginLayoutBehavior prepareForLayout(const LayoutBlock*);
     void prepareClusterStack(const LayoutObject*);
-    bool clusterHasEnoughTextToAutosize(Cluster*, const LayoutBlock* widthProvider = 0);
-    bool superclusterHasEnoughTextToAutosize(Supercluster*, const LayoutBlock* widthProvider = 0);
-    bool clusterWouldHaveEnoughTextToAutosize(const LayoutBlock* root, const LayoutBlock* widthProvider = 0);
+    bool clusterHasEnoughTextToAutosize(Cluster*, const LayoutBlock* widthProvider = nullptr);
+    bool superclusterHasEnoughTextToAutosize(Supercluster*, const LayoutBlock* widthProvider = nullptr);
+    bool clusterWouldHaveEnoughTextToAutosize(const LayoutBlock* root, const LayoutBlock* widthProvider = nullptr);
     Fingerprint getFingerprint(const LayoutObject*);
     Fingerprint computeFingerprint(const LayoutObject*);
     Cluster* maybeCreateCluster(const LayoutBlock*);
     Supercluster* getSupercluster(const LayoutBlock*);
     float clusterMultiplier(Cluster*);
     float superclusterMultiplier(Cluster*);
     // A cluster's width provider is typically the deepest block containing all text.
     // There are exceptions, such as tables and table cells which use the table itself for width.
     const LayoutBlock* clusterWidthProvider(const LayoutBlock*) const;
     const LayoutBlock* maxClusterWidthProvider(const Supercluster*, const LayoutBlock* currentRoot) const;
@@ skipping 30 matching lines @@
     FingerprintMapper m_fingerprintMapper;
     Vector<RefPtr<ComputedStyle>> m_stylesRetainedDuringLayout;
     // FIXME: All frames should share the same m_pageInfo instance.
     PageInfo m_pageInfo;
     bool m_updatePageInfoDeferred;
 };
 
 } // namespace blink
 
 #endif // TextAutosizer_h