Split the frame tree logic out of HistoryItem

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 3088 matching lines @@
     m_savedPageScaleFactor = 0;
     m_savedScrollOffset = IntSize();
 }
 
 void WebViewImpl::resetScrollAndScaleState()
 {
     page()->setPageScaleFactor(1, IntPoint());
 
     // Clear out the values for the current history item. This will prevent the history item from clobbering the
     // value determined during page scale initialization, which may be less than 1.
-    page()->mainFrame()->loader().history()->saveDocumentAndScrollState();
-    page()->mainFrame()->loader().history()->clearScrollPositionAndViewState();
+    page()->history()->saveDocumentAndScrollState(page()->mainFrame());
+    page()->history()->clearScrollPositionAndViewState();
     m_pageScaleConstraintsSet.setNeedsReset(true);
 
     // Clobber saved scales and scroll offsets.
     if (FrameView* view = page()->mainFrame()->document()->view())
         view->cacheCurrentScrollPosition();
     resetSavedScrollAndScaleState();
 }
 
 void WebViewImpl::setFixedLayoutSize(const WebSize& layoutSize)
 {
@@ skipping 1078 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink