Don't reuse HistoryItems for multiple navigations

Source/core/loader/HistoryItem.cpp

 /*
  * Copyright (C) 2005, 2006, 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 39 matching lines @@
     , m_documentSequenceNumber(generateSequenceNumber())
     , m_frameSequenceNumber(generateSequenceNumber())
     , m_scrollRestorationType(ScrollRestorationAuto)
 {
 }
 
 HistoryItem::~HistoryItem()
 {
 }
 
-void HistoryItem::generateNewItemSequenceNumber()
-{
-    m_itemSequenceNumber = generateSequenceNumber();
-}
-
-void HistoryItem::generateNewDocumentSequenceNumber()
-{
-    m_documentSequenceNumber = generateSequenceNumber();
-}
-
 const String& HistoryItem::urlString() const
 {
     return m_urlString;
 }
 
 KURL HistoryItem::url() const
 {
     return KURL(ParsedURLString, m_urlString);
 }
 
@@ skipping 42 matching lines @@
 const IntPoint& HistoryItem::scrollPoint() const
 {
     return m_scrollPoint;
 }
 
 void HistoryItem::setScrollPoint(const IntPoint& point)
 {
     m_scrollPoint = point;
 }
 
-void HistoryItem::clearScrollPoint()
-{
-    m_scrollPoint = IntPoint();
-    m_pinchViewportScrollPoint = FloatPoint();
-}
-
 float HistoryItem::pageScaleFactor() const
 {
     return m_pageScaleFactor;
 }
 
 void HistoryItem::setPageScaleFactor(float scaleFactor)
 {
     m_pageScaleFactor = scaleFactor;
 }
 
@@ skipping 69 matching lines @@
     // FIXME: We should find a better way to check if this is the current document.
     return equalIgnoringFragmentIdentifier(url(), doc->url());
 }
 
 DEFINE_TRACE(HistoryItem)
 {
     visitor->trace(m_documentState);
 }
 
 } // namespace blink