LibWeb: Make parser <script> elements delay the document load event

Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Function.h>
+#include <LibWeb/DOM/DocumentLoadEventDelayer.h>
 #include <LibWeb/HTML/HTMLElement.h>
 #include <LibWeb/HTML/Scripting/Script.h>
 
@@ -63,6 +64,8 @@ private:
     Function<void()> m_script_ready_callback;
 
     RefPtr<Script> m_script;
+
+    Optional<DOM::DocumentLoadEventDelayer> m_document_load_event_delayer;
 };
 
 }