LibWeb: Respect width and height attributes of <iframe>

We have to respect the width and height attributes of <iframe> elements
the same way as <img> elements.

Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp

@@ -9,6 +9,7 @@
 #include <LibWeb/HTML/BrowsingContext.h>
 #include <LibWeb/HTML/HTMLIFrameElement.h>
 #include <LibWeb/HTML/Origin.h>
+#include <LibWeb/HTML/Parser/HTMLParser.h>
 #include <LibWeb/Layout/FrameBox.h>
 
 namespace Web::HTML {
@@ -126,6 +127,20 @@ void HTMLIFrameElement::load_src(String const& value)
     m_nested_browsing_context->loader().load(url, FrameLoader::Type::IFrame);
 }
 
+// https://html.spec.whatwg.org/multipage/rendering.html#attributes-for-embedded-content-and-images
+void HTMLIFrameElement::apply_presentational_hints(CSS::StyleProperties& style) const
+{
+    for_each_attribute([&](auto& name, auto& value) {
+        if (name == HTML::AttributeNames::width) {
+            if (auto parsed_value = parse_dimension_value(value))
+                style.set_property(CSS::PropertyID::Width, parsed_value.release_nonnull());
+        } else if (name == HTML::AttributeNames::height) {
+            if (auto parsed_value = parse_dimension_value(value))
+                style.set_property(CSS::PropertyID::Height, parsed_value.release_nonnull());
+        }
+    });
+}
+
 // https://html.spec.whatwg.org/multipage/iframe-embed-object.html#iframe-load-event-steps
 void run_iframe_load_event_steps(HTML::HTMLIFrameElement& element)
 {

Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.h

@@ -23,6 +23,8 @@ public:
 
     void set_current_navigation_was_lazy_loaded(bool value) { m_current_navigation_was_lazy_loaded = value; }
 
+    virtual void apply_presentational_hints(CSS::StyleProperties&) const override;
+
 private:
     HTMLIFrameElement(DOM::Document&, DOM::QualifiedName);