LibWeb: Add SVGDefsElement

* Similarly to clipPath, this doesn't need to get rendered, so return no
  LayoutNode.

Userland/Libraries/LibWeb/SVG/SVGDefsElement.cpp

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2022, Simon Danner <danner.simon@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/SVG/SVGDefsElement.h>
+
+namespace Web::SVG {
+
+SVGDefsElement::SVGDefsElement(DOM::Document& document, DOM::QualifiedName qualified_name)
+    : SVGGraphicsElement(document, move(qualified_name))
+{
+}
+
+SVGDefsElement::~SVGDefsElement()
+{
+}
+
+RefPtr<Layout::Node> SVGDefsElement::create_layout_node(NonnullRefPtr<CSS::StyleProperties>)
+{
+    return nullptr;
+}
+
+}