LibWeb: Make CSS::ComputedProperties GC-allocated

Author: https://github.com/awesomekling
Commit: 74469a0c1f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2995

Libraries/LibWeb/HTML/HTMLVideoElement.cpp

@@ -63,7 +63,7 @@ void HTMLVideoElement::attribute_changed(FlyString const& name, Optional<String>
     }
 }
 
-GC::Ptr<Layout::Node> HTMLVideoElement::create_layout_node(CSS::ComputedProperties style)
+GC::Ptr<Layout::Node> HTMLVideoElement::create_layout_node(GC::Ref<CSS::ComputedProperties> style)
 {
     return heap().allocate<Layout::VideoBox>(document(), *this, move(style));
 }