Get rid of compositing and squashing helper methods on RenderLayerModelObject.

Source/core/rendering/RenderSelectionInfo.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 48 matching lines @@
 
 // This struct is used when the selection changes to cache the old and new state of the selection for each RenderObject.
 class RenderSelectionInfo : public RenderSelectionInfoBase {
 public:
     RenderSelectionInfo(RenderObject* o, bool clipToVisibleContent)
         : RenderSelectionInfoBase(o)
     {
         if (o->canUpdateSelectionOnRootLineBoxes()) {
             m_rect = o->selectionRectForPaintInvalidation(m_repaintContainer, clipToVisibleContent);
             // FIXME: groupedMapping() leaks the squashing abstraction. See RenderBlockSelectionInfo for more details.
-            if (m_repaintContainer && m_repaintContainer->groupedMapping())
+            if (m_repaintContainer && m_repaintContainer->layer()->groupedMapping())
                 RenderLayer::mapRectToPaintInvalidationBacking(m_repaintContainer, m_repaintContainer, m_rect);
         } else {
             m_rect = LayoutRect();
         }
     }
 
     void repaint()
     {
         m_object->invalidatePaintUsingContainer(m_repaintContainer, enclosingIntRect(m_rect), InvalidationSelection);
     }
@@ skipping 16 matching lines @@
         else
             m_rects = GapRects();
     }
 
     void repaint()
     {
         LayoutRect repaintRect = enclosingIntRect(m_rects);
         // FIXME: this is leaking the squashing abstraction. However, removing the groupedMapping() condiitional causes
         // RenderBox::mapRectToPaintInvalidationBacking to get called, which makes rect adjustments even if you pass the same
         // repaintContainer as the render object. Find out why it does that and fix.
-        if (m_repaintContainer && m_repaintContainer->groupedMapping())
+        if (m_repaintContainer && m_repaintContainer->layer()->groupedMapping())
             RenderLayer::mapRectToPaintInvalidationBacking(m_repaintContainer, m_repaintContainer, repaintRect);
         m_object->invalidatePaintUsingContainer(m_repaintContainer, enclosingIntRect(repaintRect), InvalidationSelection);
     }
 
     RenderBlock* block() const { return toRenderBlock(m_object); }
     GapRects rects() const { return m_rects; }
 
 private:
     GapRects m_rects; // relative to repaint container
 };
 
 } // namespace WebCore
 
 
 #endif // RenderSelectionInfo_h