Lazily generate HistoryItem's serialized form state

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)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 70 matching lines @@
 class DOMSelection;
 class DOMWindow;
 class Database;
 class DatabaseThread;
 class DocumentFragment;
 class DocumentLifecycleNotifier;
 class DocumentLifecycleObserver;
 class DocumentLoader;
 class DocumentMarkerController;
 class DocumentParser;
+class DocumentState;
 class DocumentTimeline;
 class DocumentType;
 class Element;
 class ElementDataCache;
 class Event;
 class EventListener;
 class ExceptionState;
 class FastTextAutosizer;
 class FloatQuad;
 class FloatRect;
@@ skipping 348 matching lines @@
 
     // FIXME: This should be eliminated and elements that use it should be made to
     // always have a layer so they don't need to go about creating one from reasons
     // external to style.
     void scheduleLayerUpdate(Element&);
     void unscheduleLayerUpdate(Element&);
 
     void evaluateMediaQueryList();
 
     FormController& formController();
-    Vector<String> formElementsState() const;
+    DocumentState* formElementsState() const;
     void setStateForNewFormElements(const Vector<String>&);
 
     FrameView* view() const; // can be null
     LocalFrame* frame() const { return m_frame; } // can be null
     FrameHost* frameHost() const; // can be null
     Page* page() const; // can be null
     Settings* settings() const; // can be null
 
     float devicePixelRatio() const;
 
@@ skipping 133 matching lines @@
         Loading,
         Interactive,
         Complete
     };
     void setReadyState(ReadyState);
     bool isLoadCompleted();
 
     void setParsing(bool);
     bool parsing() const { return m_isParsing; }
 
-    void setHistoryItemDocumentStateDirty(bool dirty) { m_historyItemDocumentStateDirty = dirty; }
-    bool historyItemDocumentStateDirty() const { return m_historyItemDocumentStateDirty; }
-
     bool shouldScheduleLayout() const;
     int elapsedTime() const;
 
     TextLinkColors& textLinkColors() { return m_textLinkColors; }
     VisitedLinkState& visitedLinkState() const { return *m_visitedLinkState; }
 
     MouseEventWithHitTestResults prepareMouseEvent(const HitTestRequest&, const LayoutPoint&, const PlatformMouseEvent&);
 
     /* Newly proposed CSS3 mechanism for selecting alternate
        stylesheets using the DOM. May be subject to change as
@@ skipping 610 matching lines @@
     RefPtrWillBePersistent<StyleSheetList> m_styleSheetList;
 
     OwnPtr<FormController> m_formController;
 
     TextLinkColors m_textLinkColors;
     const OwnPtr<VisitedLinkState> m_visitedLinkState;
 
     bool m_visuallyOrdered;
     ReadyState m_readyState;
     bool m_isParsing;
-    bool m_historyItemDocumentStateDirty;
 
     bool m_gotoAnchorNeededAfterStylesheetsLoad;
     bool m_isDNSPrefetchEnabled;
     bool m_haveExplicitlyDisabledDNSPrefetch;
     bool m_containsValidityStyleRules;
     bool m_updateFocusAppearanceRestoresSelection;
     bool m_containsPlugins;
 
     // http://www.whatwg.org/specs/web-apps/current-work/#ignore-destructive-writes-counter
     unsigned m_ignoreDestructiveWriteCount;
@@ skipping 175 matching lines @@
 inline bool Node::isDocumentNode() const
 {
     return this == document();
 }
 
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #endif // Document_h