Refine toRenderSVGResourceContainer()

Source/core/rendering/svg/RenderSVGGradientStop.cpp

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 37 matching lines @@
     // <stop> elements should only be allowed to make renderers under gradient elements
     // but I can imagine a few cases we might not be catching, so let's not crash if our parent isn't a gradient.
     SVGGradientElement* gradient = gradientElement();
     if (!gradient)
         return;
 
     RenderObject* renderer = gradient->renderer();
     if (!renderer)
         return;
 
-    ASSERT(renderer->isSVGResourceContainer());
-    RenderSVGResourceContainer* container = renderer->toRenderSVGResourceContainer();
+    RenderSVGResourceContainer* container = toRenderSVGResourceContainer(renderer);
     container->removeAllClientsFromCache();
 }
 
 void RenderSVGGradientStop::layout()
 {
     clearNeedsLayout();
 }
 
 SVGGradientElement* RenderSVGGradientStop::gradientElement() const
 {
     ContainerNode* parentNode = node()->parentNode();
     if (parentNode->hasTagName(linearGradientTag) || parentNode->hasTagName(radialGradientTag))
         return toSVGGradientElement(parentNode);
     return 0;
 }
 
 }