Remove painting roots.

sky/engine/core/rendering/LayerPaintingInfo.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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>
@@ skipping 36 matching lines @@
 
 #include "sky/engine/core/rendering/PaintInfo.h"
 #include "sky/engine/platform/geometry/LayoutRect.h"
 
 namespace blink {
 
 class RenderLayer;
 
 struct LayerPaintingInfo {
     LayerPaintingInfo(RenderLayer* inRootLayer, const LayoutRect& inDirtyRect,
-        const LayoutSize& inSubPixelAccumulation, RenderObject* inPaintingRoot)
+        const LayoutSize& inSubPixelAccumulation)
         : rootLayer(inRootLayer)
-        , paintingRoot(inPaintingRoot)
         , paintDirtyRect(inDirtyRect)
         , subPixelAccumulation(inSubPixelAccumulation)
         , clipToDirtyRect(true)
     { }
     RenderLayer* rootLayer;
-    RenderObject* paintingRoot; // only paint descendants of this object
     LayoutRect paintDirtyRect; // relative to rootLayer;
     LayoutSize subPixelAccumulation;
     bool clipToDirtyRect;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_RENDERING_LAYERPAINTINGINFO_H_