Pass implementation object to supplemental classes by reference

Source/core/css/FontFaceSet.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:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 78 matching lines @@
     void didLayout();
     void beginFontLoading(FontFace*);
     void fontLoaded(FontFace*);
     void loadError(FontFace*);
 
     // ActiveDOMObject
     virtual void suspend() OVERRIDE;
     virtual void resume() OVERRIDE;
     virtual void stop() OVERRIDE;
 
-    static PassRefPtr<FontFaceSet> from(Document*);
-    static void didLayout(Document*);
+    static PassRefPtr<FontFaceSet> from(Document&);
+    static void didLayout(Document&);
 
     void addFontFacesToFontFaceCache(FontFaceCache*, CSSFontSelector*);
 
 private:
     typedef RefCountedSupplement<Document, FontFaceSet> SupplementType;
 
-    static PassRefPtr<FontFaceSet> create(Document* document)
+    static PassRefPtr<FontFaceSet> create(Document& document)
     {
         return adoptRef<FontFaceSet>(new FontFaceSet(document));
     }
 
     class FontLoadHistogram {
     public:
         FontLoadHistogram() : m_count(0), m_recorded(false) { }
         void incrementCount() { m_count++; }
         void record();
 
     private:
         int m_count;
         bool m_recorded;
     };
 
-    FontFaceSet(Document*);
+    FontFaceSet(Document&);
 
     bool hasLoadedFonts() const { return !m_loadedFonts.isEmpty() || !m_failedFonts.isEmpty(); }
 
     bool inActiveDocumentContext() const;
     void forEachInternal(PassOwnPtr<FontFaceSetForEachCallback>, ScriptValue* thisArg) const;
     void incrementLoadingCount();
     void decrementLoadingCount();
     void fireLoadingEvent();
     void fireDoneEventIfPossible();
     bool resolveFontStyle(const String&, Font&);
@@ skipping 10 matching lines @@
     ListHashSet<RefPtr<FontFace> > m_nonCSSConnectedFaces;
 
     AsyncMethodRunner<FontFaceSet> m_asyncRunner;
 
     FontLoadHistogram m_histogram;
 };
 
 } // namespace WebCore
 
 #endif // FontFaceSet_h