LibWeb: Add SVG <polygon> element and test case :^)

Author: https://github.com/AtkinsSJ
Commit: 2fad940b0b
Pull-request: https://github.com/SerenityOS/serenity/pull/12444
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/SVG/SVGPolygonElement.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/SVG/SVGGeometryElement.h>
+
+namespace Web::SVG {
+
+class SVGPolygonElement final : public SVGGeometryElement {
+public:
+    using WrapperType = Bindings::SVGPolygonElementWrapper;
+
+    SVGPolygonElement(DOM::Document&, QualifiedName);
+    virtual ~SVGPolygonElement() override = default;
+
+    virtual void parse_attribute(FlyString const& name, String const& value) override;
+
+    virtual Gfx::Path& get_path() override;
+
+private:
+    Optional<Gfx::Path> m_path;
+
+    Vector<Gfx::FloatPoint> m_points;
+};
+
+}