LibWeb: Implement HTMLIFrameElement.referrerPolicy

Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp

@@ -133,8 +133,8 @@ void HTMLIFrameElement::process_the_iframe_attributes(bool initial_insertion)
         return;
     }
 
-    // FIXME: 4. Let referrerPolicy be the current state of element's referrerpolicy content attribute.
-    auto referrer_policy = ReferrerPolicy::ReferrerPolicy::EmptyString;
+    // 4. Let referrerPolicy be the current state of element's referrerpolicy content attribute.
+    auto referrer_policy = ReferrerPolicy::from_string(get_attribute_value(HTML::AttributeNames::referrerpolicy)).value_or(ReferrerPolicy::ReferrerPolicy::EmptyString);
 
     // 5. Set element's current navigation was lazy loaded boolean to false.
     set_current_navigation_was_lazy_loaded(false);

Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.idl

@@ -16,7 +16,7 @@ interface HTMLIFrameElement : HTMLElement {
     [CEReactions, Reflect=allowfullscreen] attribute boolean allowFullscreen;
     [CEReactions, Reflect] attribute DOMString width;
     [CEReactions, Reflect] attribute DOMString height;
-    [FIXME, CEReactions] attribute DOMString referrerPolicy;
+    [CEReactions, Reflect=referrerpolicy, Enumerated=ReferrerPolicy] attribute DOMString referrerPolicy;
     [CEReactions, Enumerated=LazyLoadingAttribute, Reflect] attribute DOMString loading;
     readonly attribute Document? contentDocument;
     readonly attribute WindowProxy? contentWindow;