Reland "Remove children from HistoryNodes that redirect during back/forward navigation"

Source/core/page/HistoryController.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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.
@@ skipping 83 matching lines @@
 class HistoryNode {
 public:
     static PassOwnPtr<HistoryNode> create(HistoryEntry*, HistoryItem*);
     ~HistoryNode() { }
 
     HistoryNode* addChild(PassRefPtr<HistoryItem>);
     PassOwnPtr<HistoryNode> cloneAndReplace(HistoryEntry*, HistoryItem* newItem, bool clipAtTarget, Frame* targetFrame, Frame* currentFrame);
     HistoryItem* value() { return m_value.get(); }
     void updateValue(PassRefPtr<HistoryItem> item) { m_value = item; }
     const Vector<OwnPtr<HistoryNode> >& children() const { return m_children; }
+    void removeChildren();
 
 private:
     HistoryNode(HistoryEntry*, HistoryItem*);
 
     HistoryEntry* m_entry;
     Vector<OwnPtr<HistoryNode> > m_children;
     RefPtr<HistoryItem> m_value;
+
 };
 
 class HistoryEntry {
 public:
     static PassOwnPtr<HistoryEntry> create(HistoryItem* root);
     PassOwnPtr<HistoryEntry> cloneAndReplace(HistoryItem* newItem, bool clipAtTarget, Frame* targetFrame, Page*);
 
     HistoryNode* historyNodeForFrame(Frame*);
     HistoryItem* itemForFrame(Frame*);
     HistoryItem* root() const { return m_root->value(); }
@@ skipping 19 matching lines @@
     // Should only be called by embedder. To request a back/forward
     // navigation, call FrameLoaderClient::navigateBackForward().
     void goToItem(HistoryItem*, ResourceRequestCachePolicy);
 
     void updateBackForwardListForFragmentScroll(Frame*, HistoryItem*);
     void updateForCommit(Frame*, HistoryItem*, HistoryCommitType);
 
     PassRefPtr<HistoryItem> currentItemForExport();
     PassRefPtr<HistoryItem> previousItemForExport();
     HistoryItem* itemForNewChildFrame(Frame*) const;
+    void removeChildrenForRedirect(Frame*);
 
     void setDefersLoading(bool);
 
 private:
     void goToEntry(PassOwnPtr<HistoryEntry>, ResourceRequestCachePolicy);
     typedef HashMap<Frame*, HistoryItem*> HistoryFrameLoadSet;
     void recursiveGoToEntry(Frame*, HistoryFrameLoadSet& sameDocumentLoads, HistoryFrameLoadSet& differentDocumentLoads);
 
     void updateForInitialLoadInChildFrame(Frame*, HistoryItem*);
     void createNewBackForwardItem(Frame*, HistoryItem*, bool doClip);
 
     Page* m_page;
 
     OwnPtr<HistoryEntry> m_currentEntry;
     OwnPtr<HistoryEntry> m_previousEntry;
     OwnPtr<HistoryEntry> m_provisionalEntry;
 
     bool m_defersLoading;
     RefPtr<HistoryItem> m_deferredItem;
     ResourceRequestCachePolicy m_deferredCachePolicy;
 };
 
 } // namespace WebCore
 
 #endif // HistoryController_h