Split the frame tree logic out of HistoryItem

Source/web/WebFrameImpl.cpp

Index: Source/web/WebFrameImpl.cpp
diff --git a/Source/web/WebFrameImpl.cpp b/Source/web/WebFrameImpl.cpp
index e6c209c3648a07d629b48e8457e1350eba198ec9..423e4011607d49e28f4e4b6a343cd1ff62df0ac2 100644
--- a/Source/web/WebFrameImpl.cpp
+++ b/Source/web/WebFrameImpl.cpp
@@ -924,8 +924,7 @@ void WebFrameImpl::loadHistoryItem(const WebHistoryItem& item)
     ASSERT(historyItem);
 
     frame()->loader()->prepareForHistoryNavigation();
-    RefPtr<HistoryItem> currentItem = frame()->loader()->history()->currentItem();
-    m_inSameDocumentHistoryLoad = currentItem && currentItem->shouldDoSameDocumentNavigationTo(historyItem.get());
+    m_inSameDocumentHistoryLoad = frame()->loader()->shouldTreatURLAsSameAsCurrent(historyItem->url());
     frame()->page()->goToItem(historyItem.get());
     m_inSameDocumentHistoryLoad = false;
 }
@@ -998,7 +997,7 @@ WebHistoryItem WebFrameImpl::previousHistoryItem() const
     // only get saved to history when it becomes the previous item.  The caller
     // is expected to query the history item after a navigation occurs, after
     // the desired history item has become the previous entry.
-    return WebHistoryItem(frame()->loader()->history()->previousItem());
+    return WebHistoryItem(frame()->loader()->history()->previousItemForExport(frame()));
 }
 
 WebHistoryItem WebFrameImpl::currentHistoryItem() const
@@ -1016,11 +1015,11 @@ WebHistoryItem WebFrameImpl::currentHistoryItem() const
     // clobbering here?
     if (!m_inSameDocumentHistoryLoad && (frame()->loader()->loadType() == FrameLoadTypeStandard
         || !frame()->loader()->activeDocumentLoader()->isLoadingInAPISense()))
-        frame()->loader()->history()->saveDocumentAndScrollState();
+        frame()->loader()->history()->saveDocumentAndScrollState(frame());
 
-    if (HistoryItem* item = frame()->loader()->history()->provisionalItem())
+    if (RefPtr<HistoryItem> item = frame()->loader()->history()->provisionalItemForExport(frame()))
         return WebHistoryItem(item);
-    return WebHistoryItem(frame()->page()->mainFrame()->loader()->history()->currentItem());
+    return WebHistoryItem(frame()->loader()->history()->currentItemForExport(frame()));
 }
 
 void WebFrameImpl::enableViewSourceMode(bool enable)
@@ -2193,12 +2192,12 @@ PassRefPtr<Frame> WebFrameImpl::createChildFrame(const FrameLoadRequest& request
     if (!childFrame->tree()->parent())
         return 0;
 
-    HistoryItem* parentItem = frame()->loader()->history()->currentItem();
+    HistoryItem* parentItem = frame()->loader()->history()->currentItem(frame());
     HistoryItem* childItem = 0;
     // If we're moving in the back/forward list, we might want to replace the content
     // of this child frame with whatever was there at that point.
-    if (parentItem && parentItem->children().size() && isBackForwardLoadType(frame()->loader()->loadType()) && !frame()->document()->loadEventFinished())
-        childItem = parentItem->childItemWithTarget(childFrame->tree()->uniqueName());
+    if (parentItem && isBackForwardLoadType(frame()->loader()->loadType()) && !frame()->document()->loadEventFinished())
+        childItem = frame()->loader()->history()->currentItem(childFrame.get());
 
     if (childItem)
         childFrame->loader()->loadHistoryItem(childItem);