Fix treatment of non-autosizing containers.

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 49 matching lines @@
 
     void record(RenderBlock*);
     void destroy(RenderBlock*);
 
     void beginLayout(RenderBlock*);
     void inflate(RenderBlock*);
     void endLayout(RenderBlock*);
 
 private:
     struct Cluster {
-        explicit Cluster(RenderBlock* root, float multiplier)
+        explicit Cluster(RenderBlock* root, bool autosize, float multiplier)
             : m_root(root)
+            , m_autosize(autosize)
             , m_multiplier(multiplier)
         {
         }
         RenderBlock* m_root;
+        bool m_autosize;

[pdr., 2014/01/14 02:50:03]

Can you add a comment here (or above Cluster) that describes how this works?
Maybe just state that clusters can enable or suppress autosizing for their
non-cluster-subtree children?

         float m_multiplier;
     };
 
     typedef WTF::HashSet<RenderBlock*> BlockSet;
     typedef WTF::HashMap<RenderBlock*, OwnPtr<Cluster> > ClusterMap;
     typedef WTF::Vector<Cluster*> ClusterStack;
 
     // Fingerprints are computed during style recalc, for (some subset of)
     // blocks that will become cluster roots.
     class FingerprintMapper {
     public:
         void add(RenderBlock*, AtomicString);
         void remove(RenderBlock*);
         AtomicString get(RenderBlock*);
         BlockSet& getBlocks(AtomicString);
     private:
         typedef WTF::HashMap<RenderBlock*, AtomicString> FingerprintMap;
         typedef WTF::HashMap<AtomicString, OwnPtr<BlockSet> > ReverseFingerprintMap;
 
         FingerprintMap m_fingerprints;
         ReverseFingerprintMap m_blocksForFingerprint;
     };
 
     explicit FastTextAutosizer(Document*);
 
     bool enabled();
     void prepareRenderViewInfo(RenderView*);
-    bool shouldBeClusterRoot(RenderBlock*);
+    bool isFingerprintingCandidate(RenderBlock*);
     bool clusterWantsAutosizing(RenderBlock*);
     AtomicString computeFingerprint(RenderBlock*);
-    Cluster* getOrCreateCluster(RenderBlock*);
-    Cluster* createCluster(RenderBlock*);
+    Cluster* maybeGetOrCreateCluster(RenderBlock*);
     Cluster* addSupercluster(AtomicString, RenderBlock*);
     RenderBlock* deepestCommonAncestor(BlockSet&);
     float computeMultiplier(RenderBlock*);
     void applyMultiplier(RenderObject*, float);
 
     Document* m_document;
     int m_windowWidth; // Frame width in density-independent pixels (DIPs).
     int m_layoutWidth; // Layout width in CSS pixels.
     float m_baseMultiplier; // Includes accessibility font scale factor and device scale adjustment.
 #ifndef NDEBUG
     bool m_renderViewInfoPrepared; // Used for assertions.
 #endif
 
     // Clusters are created and destroyed during layout. The map key is the
     // cluster root. Clusters whose roots share the same fingerprint use the
     // same multiplier.
     ClusterMap m_clusters;
     ClusterStack m_clusterStack;
     FingerprintMapper m_fingerprintMapper;
 };
 
 } // namespace WebCore
 
 #endif // FastTextAutosizer_h