Split the frame tree logic out of HistoryItem

Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 34 matching lines @@
 class ContextMenuController;
 class Document;
 class DragCaretController;
 class DragClient;
 class DragController;
 class EditorClient;
 class FocusController;
 class Frame;
 class FrameSelection;
 class HaltablePlugin;
+class HistoryController;
 class HistoryItem;
 class InspectorClient;
 class InspectorController;
 class Node;
 class PageConsole;
 class PageGroup;
 class PageLifecycleNotifier;
 class PlatformMouseEvent;
 class PluginData;
 class PointerLockController;
@@ skipping 40 matching lines @@
 
     void setNeedsRecalcStyleInAllFrames();
 
     ViewportDescription viewportDescription() const;
 
     static void refreshPlugins(bool reload);
     PluginData* pluginData() const;
 
     EditorClient& editorClient() const { return *m_editorClient; }
 
+    HistoryController* history() const { return m_history.get(); }
+
     void setMainFrame(PassRefPtr<Frame>);
     Frame* mainFrame() const { return m_mainFrame.get(); }
 
     void documentDetached(Document*);
 
     bool openedByDOM() const;
     void setOpenedByDOM();
 
     // DEPRECATED. Use backForward() instead of the following function.
     void goToItem(HistoryItem*);
@@ skipping 132 matching lines @@
     const OwnPtr<AutoscrollController> m_autoscrollController;
     const OwnPtr<Chrome> m_chrome;
     const OwnPtr<DragCaretController> m_dragCaretController;
     const OwnPtr<DragController> m_dragController;
     const OwnPtr<FocusController> m_focusController;
     const OwnPtr<ContextMenuController> m_contextMenuController;
     const OwnPtr<InspectorController> m_inspectorController;
     const OwnPtr<PointerLockController> m_pointerLockController;
     RefPtr<ScrollingCoordinator> m_scrollingCoordinator;
 
+    const OwnPtr<HistoryController> m_history;
     const OwnPtr<Settings> m_settings;
     const OwnPtr<ProgressTracker> m_progress;
 
     RefPtr<Frame> m_mainFrame;
 
     mutable RefPtr<PluginData> m_pluginData;
 
     BackForwardClient* m_backForwardClient;
     EditorClient* const m_editorClient;
     ValidationMessageClient* m_validationMessageClient;
@@ skipping 30 matching lines @@
 #endif
 
     const OwnPtr<PageConsole> m_console;
 
     HashSet<MultisamplingChangedObserver*> m_multisamplingChangedObservers;
 };
 
 } // namespace WebCore
 
 #endif // Page_h