Move RenderSVGResource::cast() to RenderSVGResourceContainer

Source/core/rendering/svg/RenderSVGResource.h

Index: Source/core/rendering/svg/RenderSVGResource.h
diff --git a/Source/core/rendering/svg/RenderSVGResource.h b/Source/core/rendering/svg/RenderSVGResource.h
index 653594a52fa51652bbe464983f148cf775b445eb..df2cb2a2cd32301584ac770e1fe2542112498857 100644
--- a/Source/core/rendering/svg/RenderSVGResource.h
+++ b/Source/core/rendering/svg/RenderSVGResource.h
@@ -59,15 +59,6 @@ public:
 
     virtual RenderSVGResourceType resourceType() const = 0;
 
-    template<class Renderer>
-    Renderer* cast()
-    {
-        if (Renderer::s_resourceType == resourceType())
-            return static_cast<Renderer*>(this);
-
-        return 0;
-    }
-
     // Helper utilities used in the render tree to access resources used for painting shapes/text (gradients & patterns & solid colors only)
     // If hasFallback gets set to true, the sharedSolidPaintingResource is set to a fallback color.
     static RenderSVGResource* requestPaintingResource(RenderSVGResourceMode, RenderObject*, const RenderStyle*, bool& hasFallback);