Remove ancestor walk for non-SVG RenderObjects in willBeRemovedFromTree()

Source/core/rendering/svg/RenderSVGModelObject.h

 /*
  * Copyright (c) 2009, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 49 matching lines @@
     virtual const RenderObject* pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap&) const OVERRIDE FINAL;
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
 
     static bool checkIntersection(RenderObject*, const SVGRect&);
     static bool checkEnclosure(RenderObject*, const SVGRect&);
 
     virtual void computeLayerHitTestRects(LayerHitTestRects&) const OVERRIDE;
 
     SVGElement* element() const { return toSVGElement(RenderObject::node()); }
 
+    virtual bool isSVG() const OVERRIDE FINAL { return true; }
+
 protected:
     virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const OVERRIDE;
     virtual void willBeDestroyed();
 
 private:
     // RenderSVGModelObject subclasses should use element() instead.
     void node() const WTF_DELETED_FUNCTION;
 
     // This method should never be called, SVG uses a different nodeAtPoint method
     bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) OVERRIDE;
     virtual void absoluteFocusRingQuads(Vector<FloatQuad>&) OVERRIDE FINAL;
 };
 
 }
 
 #endif