Merge 93296 - Prepare frames for history navigation.

Source/WebCore/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 1064 matching lines @@
     if (m_frame->view())
         m_frame->view()->maintainScrollPositionAtAnchor(0);
 }
 
 void FrameLoader::started()
 {
     for (Frame* frame = m_frame; frame; frame = frame->tree()->parent())
         frame->loader()->m_isComplete = false;
 }
 
+void FrameLoader::prepareForHistoryNavigation()
+{
+    // If there is no currentItem, but we still want to engage in 
+    // history navigation we need to manufacture one, and update
+    // the state machine of this frame to impersonate having
+    // loaded it.
+    RefPtr<HistoryItem> currentItem = history()->currentItem();
+    if (!currentItem) {
+        currentItem = HistoryItem::create();
+        currentItem->setLastVisitWasFailure(true);
+        history()->setCurrentItem(currentItem.get());
+        frame()->page()->backForward()->setCurrentItem(currentItem.get());
+
+        ASSERT(stateMachine()->isDisplayingInitialEmptyDocument());
+        stateMachine()->advanceTo(FrameLoaderStateMachine::DisplayingInitialEmptyDocumentPostCommit);
+        stateMachine()->advanceTo(FrameLoaderStateMachine::CommittedFirstRealLoad);
+    }
+}
+
 void FrameLoader::prepareForLoadStart()
 {
     if (Page* page = m_frame->page())
         page->progress()->progressStarted(m_frame);
     m_client->dispatchDidStartProvisionalLoad();
 }
 
 void FrameLoader::setupForReplace()
 {
     setState(FrameStateProvisional);
@@ skipping 2189 matching lines @@
         windowRect.setHeight(features.height + (windowRect.height() - pageSize.height()));
     page->chrome()->setWindowRect(windowRect);
 
     page->chrome()->show();
 
     created = true;
     return frame;
 }
 
 } // namespace WebCore