Use DEFINE_NODE_TYPE_CASTS instead of using manual toHTMLFooElement()

Source/core/html/HTMLFrameOwnerElement.h

Index: Source/core/html/HTMLFrameOwnerElement.h
diff --git a/Source/core/html/HTMLFrameOwnerElement.h b/Source/core/html/HTMLFrameOwnerElement.h
index ed1b7abbbd26b6ec7f25e979e8616d0ceea740f3..2e7c9186914aaed7a24863cdd163eebcd1f0394b 100644
--- a/Source/core/html/HTMLFrameOwnerElement.h
+++ b/Source/core/html/HTMLFrameOwnerElement.h
@@ -77,17 +77,7 @@ private:
     SandboxFlags m_sandboxFlags;
 };
 
-inline HTMLFrameOwnerElement* toHTMLFrameOwnerElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isFrameOwnerElement());
-    return static_cast<HTMLFrameOwnerElement*>(node);
-}
-
-inline const HTMLFrameOwnerElement* toHTMLFrameOwnerElement(const Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isFrameOwnerElement());
-    return static_cast<const HTMLFrameOwnerElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(HTMLFrameOwnerElement, isFrameOwnerElement());
 
 class SubframeLoadingDisabler {
 public: