LibWeb: Port the CSS namespace to IDL

Author: https://github.com/trflynn89
Commit: 2d45e1fca5
Pull-request: https://github.com/SerenityOS/serenity/pull/17870
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibWeb/CSS/CSS.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
+ * Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <AK/StringView.h>
+#include <LibJS/Forward.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+// https://www.w3.org/TR/cssom-1/#namespacedef-css
+namespace Web::CSS {
+
+WebIDL::ExceptionOr<String> escape(JS::VM&, StringView identifier);
+
+bool supports(JS::VM&, StringView property, StringView value);
+WebIDL::ExceptionOr<bool> supports(JS::VM&, StringView condition_text);
+
+}