Add a unique frame id and save it on HistoryItem.

Source/core/history/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 32 matching lines @@
     // Initialize to the current time to reduce the likelihood of generating
     // identifiers that overlap with those from past/future browser sessions.
     static long long next = static_cast<long long>(currentTime() * 1000000.0);
     return ++next;
 }
 
 HistoryItem::HistoryItem()
     : m_pageScaleFactor(0)
     , m_itemSequenceNumber(generateSequenceNumber())
     , m_documentSequenceNumber(generateSequenceNumber())
+    , m_targetFrameID(0)
 {
 }
 
 HistoryItem::~HistoryItem()
 {
 }
 
 inline HistoryItem::HistoryItem(const HistoryItem& item)
     : RefCounted<HistoryItem>()
     , m_urlString(item.m_urlString)
     , m_originalURLString(item.m_originalURLString)
     , m_referrer(item.m_referrer)
     , m_target(item.m_target)
     , m_scrollPoint(item.m_scrollPoint)
     , m_pageScaleFactor(item.m_pageScaleFactor)
     , m_itemSequenceNumber(item.m_itemSequenceNumber)
     , m_documentSequenceNumber(item.m_documentSequenceNumber)
+    , m_targetFrameID(item.m_targetFrameID)
+    , m_stateObject(item.m_stateObject)
     , m_formContentType(item.m_formContentType)
 {
     if (item.m_formData)
         m_formData = item.m_formData->copy();
 
     unsigned size = item.m_children.size();
     m_children.reserveInitialCapacity(size);
     for (unsigned i = 0; i < size; ++i)
         m_children.uncheckedAppend(item.m_children[i]->copy());
 }
 
 PassRefPtr<HistoryItem> HistoryItem::copy() const
 {
     return adoptRef(new HistoryItem(*this));
 }
 
 void HistoryItem::reset()
 {
     m_urlString = String();
     m_originalURLString = String();
     m_referrer = String();
     m_target = String();
     m_itemSequenceNumber = generateSequenceNumber();
     m_stateObject = 0;
     m_documentSequenceNumber = generateSequenceNumber();
+    m_targetFrameID = 0;
     m_formData = 0;
     m_formContentType = String();
     clearChildren();
 }
 
 const String& HistoryItem::urlString() const
 {
     return m_urlString;
 }
 
@@ skipping 268 matching lines @@
 } // namespace WebCore
 
 #ifndef NDEBUG
 
 int showTree(const WebCore::HistoryItem* item)
 {
     return item->showTree();
 }
 
 #endif