Remove a bunch of dead code from RenderLayer

sky/engine/core/rendering/RenderLayerClipper.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 304 matching lines @@
 {
     if (context.usesCache())
         clipRects = *getClipRects(context);
     else
         calculateClipRects(context, clipRects);
 }
 
 RenderLayer* RenderLayerClipper::clippingRootForPainting() const
 {
     const RenderLayer* current = m_renderer.layer();
-    if (current->isPaintInvalidationContainer())
-        return const_cast<RenderLayer*>(current);
-
     while (current) {
         if (current->isRootLayer())
             return const_cast<RenderLayer*>(current);
 
         current = current->compositingContainer();
         ASSERT(current);
-        if (current->transform() || current->isPaintInvalidationContainer())
+        if (current->transform())
             return const_cast<RenderLayer*>(current);
     }
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 } // namespace blink