Get rid of compositing and squashing helper methods on RenderLayerModelObject.

Source/core/rendering/RenderLayerRepainter.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 107 matching lines @@
 
         if (absRect.isEmpty())
             return;
 
         RenderView* view = m_renderer.view();
         if (view)
             view->repaintViewRectangle(absRect);
         return;
     }
     IntRect repaintRect = pixelSnappedIntRect(r);
-    // FIXME: generalize accessors to backing GraphicsLayers so that this code is squashing-agnostic.
-    if (m_renderer.groupedMapping()) {
-        if (GraphicsLayer* squashingLayer = m_renderer.groupedMapping()->squashingLayer())
+    // FIXME: generalize accessors to backing GraphicsLayers so that this code is squasphing-agnostic.
+    if (m_renderer.layer()->groupedMapping()) {
+        if (GraphicsLayer* squashingLayer = m_renderer.layer()->groupedMapping()->squashingLayer())
             squashingLayer->setNeedsDisplayInRect(repaintRect);
     } else {
-        m_renderer.compositedLayerMapping()->setContentsNeedDisplayInRect(repaintRect);
+        m_renderer.layer()->compositedLayerMapping()->setContentsNeedDisplayInRect(repaintRect);
     }
 }
 
 void RenderLayerRepainter::setFilterBackendNeedsRepaintingInRect(const LayoutRect& rect)
 {
     if (rect.isEmpty())
         return;
     LayoutRect rectForRepaint = rect;
     m_renderer.style()->filterOutsets().expandRect(rectForRepaint);
 
@@ skipping 31 matching lines @@
 RenderLayer* RenderLayerRepainter::enclosingFilterRepaintLayer() const
 {
     for (const RenderLayer* curr = m_renderer.layer(); curr; curr = curr->parent()) {
         if ((curr != m_renderer.layer() && curr->requiresFullLayerImageForFilters()) || curr->compositingState() == PaintsIntoOwnBacking || curr->isRootLayer())
             return const_cast<RenderLayer*>(curr);
     }
     return 0;
 }
 
 } // Namespace WebCore