Remove painting roots.

sky/engine/core/rendering/PaintInfo.h

Index: sky/engine/core/rendering/PaintInfo.h
diff --git a/sky/engine/core/rendering/PaintInfo.h b/sky/engine/core/rendering/PaintInfo.h
index 8a2ad09968dab42e20896a3a8f39dfeea7afd171..56490167c5e9f244f6791dde440f0fcde00fc53b 100644
--- a/sky/engine/core/rendering/PaintInfo.h
+++ b/sky/engine/core/rendering/PaintInfo.h
@@ -47,32 +47,14 @@ class RenderObject;
  */
 struct PaintInfo {
     PaintInfo(GraphicsContext* newContext, const IntRect& newRect, PaintPhase newPhase,
-        RenderObject* newPaintingRoot, const RenderLayerModelObject* newPaintContainer)
+        const RenderLayerModelObject* newPaintContainer)
         : context(newContext)
         , rect(newRect)
         , phase(newPhase)
-        , paintingRoot(newPaintingRoot)
         , m_paintContainer(newPaintContainer)
     {
     }
 
-    void updatePaintingRootForChildren(const RenderObject* renderer)
-    {
-        if (!paintingRoot)
-            return;
-
-        // If we're the painting root, kids draw normally, and see root of 0.
-        if (paintingRoot == renderer) {
-            paintingRoot = 0;
-            return;
-        }
-    }
-
-    bool shouldPaintWithinRoot(const RenderObject* renderer) const
-    {
-        return !paintingRoot || paintingRoot == renderer;
-    }
-
     void applyTransform(const AffineTransform& localToAncestorTransform, bool identityStatusUnknown = true)
     {
         if (identityStatusUnknown && localToAncestorTransform.isIdentity())
@@ -96,7 +78,6 @@ struct PaintInfo {
     GraphicsContext* context;
     IntRect rect;
     PaintPhase phase;
-    RenderObject* paintingRoot; // used to draw just one element and its visual kids
 
 private:
     const RenderLayerModelObject* m_paintContainer; // the layer object that originates the current painting