[FastTextAutosizer] Keep m_blocksForFingerprint and m_fingerprints in sync

Source/core/rendering/FastTextAutosizer.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 159 matching lines @@
         void addTentativeClusterRoot(const RenderBlock*, Fingerprint);
         void remove(const RenderObject*);
         Fingerprint get(const RenderObject*);
         BlockSet& getTentativeClusterRoots(Fingerprint);
     private:
         typedef HashMap<const RenderObject*, Fingerprint> FingerprintMap;
         typedef HashMap<Fingerprint, OwnPtr<BlockSet> > ReverseFingerprintMap;
 
         FingerprintMap m_fingerprints;
         ReverseFingerprintMap m_blocksForFingerprint;
+#ifndef NDEBUG
+        bool mapsAreConsistent();
+#endif
     };
 
     explicit FastTextAutosizer(const Document*);
 
     void beginLayout(RenderBlock*);
     void endLayout(RenderBlock*);
     void inflateTable(RenderTable*);
     void inflate(RenderBlock*);
     bool enabled();
     void updateRenderViewInfo();
@@ skipping 47 matching lines @@
     // cluster root. Clusters whose roots share the same fingerprint use the
     // same multiplier.
     SuperclusterMap m_superclusters;
     ClusterStack m_clusterStack;
     FingerprintMapper m_fingerprintMapper;
 };
 
 } // namespace WebCore
 
 #endif // FastTextAutosizer_h