Use DEFINE_NODE_TYPE_CASTS instead of using manual toHTMLFooElement()

Source/core/html/HTMLElement.h

Index: Source/core/html/HTMLElement.h
diff --git a/Source/core/html/HTMLElement.h b/Source/core/html/HTMLElement.h
index 9c56c7815f4640294663e60b19a2d6dbd76561ec..e58a25efc436ccc9a8fc7a16bda9fcf0e1e22b3c 100644
--- a/Source/core/html/HTMLElement.h
+++ b/Source/core/html/HTMLElement.h
@@ -136,20 +136,7 @@ private:
     bool supportsSpatialNavigationFocus() const;
 };
 
-inline HTMLElement* toHTMLElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isHTMLElement());
-    return static_cast<HTMLElement*>(node);
-}
-
-inline const HTMLElement* toHTMLElement(const Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isHTMLElement());
-    return static_cast<const HTMLElement*>(node);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toHTMLElement(const HTMLElement*);
+DEFINE_NODE_TYPE_CASTS(HTMLElement, isHTMLElement());
 
 inline HTMLElement::HTMLElement(const QualifiedName& tagName, Document& document, ConstructionType type = CreateHTMLElement)
     : Element(tagName, &document, type)