[WIP] Use the flat tree for hover handling.

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 690 matching lines @@
     return m_userActionElements;
   }
   void setAutofocusElement(Element*);
   Element* autofocusElement() const { return m_autofocusElement.get(); }
   void setSequentialFocusNavigationStartingPoint(Node*);
   Element* sequentialFocusNavigationStartingPoint(WebFocusType) const;
 
   void setActiveHoverElement(Element*);
   Element* activeHoverElement() const { return m_activeHoverElement.get(); }
 
-  Node* hoverNode() const { return m_hoverNode.get(); }
+  Element* hoverElement() const { return m_hoverElement.get(); }
 
   void removeFocusedElementOfSubtree(Node*, bool amongChildrenOnly = false);
   void hoveredNodeDetached(Element&);
   void activeChainNodeDetached(Element&);
 
   void updateHoverActiveState(const HitTestRequest&, Element*, Scrollbar*);
 
   // Updates for :target (CSS3 selector).
   void setCSSTarget(Element*);
   Element* cssTarget() const { return m_cssTarget; }
@@ skipping 671 matching lines @@
 
   void didAssociateFormControlsTimerFired(TimerBase*);
 
   void clearFocusedElementSoon();
   void clearFocusedElementTimerFired(TimerBase*);
 
   bool haveScriptBlockingStylesheetsLoaded() const;
   bool haveRenderBlockingStylesheetsLoaded() const;
   void styleResolverMayHaveChanged();
 
-  void setHoverNode(Node*);
+  void setHoverElement(Element*);
 
   using EventFactorySet = HashSet<std::unique_ptr<EventFactoryBase>>;
   static EventFactorySet& eventFactories();
 
   void setNthIndexCache(NthIndexCache* nthIndexCache) {
     DCHECK(!m_nthIndexCache || !nthIndexCache);
     m_nthIndexCache = nthIndexCache;
   }
 
   const OriginAccessEntry& accessEntryFromURL();
@@ skipping 54 matching lines @@
   // This is cheaper than making setCompatibilityMode virtual.
   bool m_compatibilityModeLocked;
 
   TaskHandle m_executeScriptsWaitingForResourcesTaskHandle;
 
   bool m_hasAutofocused;
   TaskRunnerTimer<Document> m_clearFocusedElementTimer;
   Member<Element> m_autofocusElement;
   Member<Element> m_focusedElement;
   Member<Range> m_sequentialFocusNavigationStartingPoint;
-  Member<Node> m_hoverNode;
+  Member<Element> m_hoverElement;
   Member<Element> m_activeHoverElement;
   Member<Element> m_documentElement;
   UserActionElementSet m_userActionElements;
   Member<RootScrollerController> m_rootScrollerController;
 
   uint64_t m_domTreeVersion;
   static uint64_t s_globalTreeVersion;
 
   uint64_t m_styleVersion;
 
@@ skipping 221 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif  // Document_h