Implement <select> Popup Menu using PagePopup

Source/core/css/CSSFontSelector.h

 /*
  * Copyright (C) 2007, 2008, 2011 Apple 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 23 matching lines @@
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 
 namespace blink {
 
 class CSSFontSelectorClient;
 class Document;
 class FontDescription;
 
-class CSSFontSelector final : public FontSelector {
+class CSSFontSelector : public FontSelector {
 public:
     static PassRefPtrWillBeRawPtr<CSSFontSelector> create(Document* document)
     {
         return adoptRefWillBeNoop(new CSSFontSelector(document));
     }
     virtual ~CSSFontSelector();
 
     virtual unsigned version() const override { return m_fontFaceCache.version(); }
 
     virtual PassRefPtr<FontData> getFontData(const FontDescription&, const AtomicString&) override;
@@ skipping 16 matching lines @@
 
     Document* document() const { return m_document; }
     FontFaceCache* fontFaceCache() { return &m_fontFaceCache; }
     FontLoader* fontLoader() { return m_fontLoader.get(); }
 
     const GenericFontFamilySettings& genericFontFamilySettings() const { return m_genericFontFamilySettings; }
     void updateGenericFontFamilySettings(Document&);
 
     virtual void trace(Visitor*) override;
 
+protected:
+    explicit CSSFontSelector(Document*);
+
 private:
-    explicit CSSFontSelector(Document*);
 
     void dispatchInvalidationCallbacks();
 
     // FIXME: Oilpan: Ideally this should just be a traced Member but that will
     // currently leak because RenderStyle and its data are not on the heap.
     // See crbug.com/383860 for details.
     RawPtrWillBeWeakMember<Document> m_document;
     // FIXME: Move to Document or StyleEngine.
     FontFaceCache m_fontFaceCache;
     WillBeHeapHashSet<RawPtrWillBeWeakMember<CSSFontSelectorClient> > m_clients;
 
     RefPtrWillBeMember<FontLoader> m_fontLoader;
     GenericFontFamilySettings m_genericFontFamilySettings;
 };
 
 } // namespace blink
 
 #endif // CSSFontSelector_h