Refine toRenderSVGResourceContainer()

Source/core/rendering/svg/RenderSVGResourceContainer.h

Index: Source/core/rendering/svg/RenderSVGResourceContainer.h
diff --git a/Source/core/rendering/svg/RenderSVGResourceContainer.h b/Source/core/rendering/svg/RenderSVGResourceContainer.h
index 9489a6f8a2db7e93ba08436a8be96925b2ee0dc5..3965093b00889038116a7714f7edc08cb920944a 100644
--- a/Source/core/rendering/svg/RenderSVGResourceContainer.h
+++ b/Source/core/rendering/svg/RenderSVGResourceContainer.h
@@ -37,7 +37,6 @@ public:
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE FINAL;
 
     virtual bool isSVGResourceContainer() const OVERRIDE FINAL { return true; }
-    virtual RenderSVGResourceContainer* toRenderSVGResourceContainer() OVERRIDE FINAL { return this; }
 
     static bool shouldTransformOnTextPainting(RenderObject*, AffineTransform&);
     static AffineTransform transformOnNonScalingStroke(RenderObject*, const AffineTransform& resourceTransform);
@@ -97,6 +96,21 @@ Renderer* getRenderSVGResourceById(Document& document, const AtomicString& id)
     return 0;
 }
 
+inline RenderSVGResourceContainer* toRenderSVGResourceContainer(RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGResourceContainer());
+    return static_cast<RenderSVGResourceContainer*>(object);
+}
+
+inline const RenderSVGResourceContainer* toRenderSVGResourceContainer(const RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGResourceContainer());
+    return static_cast<const RenderSVGResourceContainer*>(object);
+}
+
+// This will catch anyone doing an unnecessary cast.
+void toRenderSVGResourceContainer(const RenderSVGResourceContainer*);
+
 }
 
 #endif