LibWeb: Light dismiss popovers on click

Author: https://github.com/Gingeh
Commit: 1f1884da54
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4428
Reviewed-by: https://github.com/AtkinsSJ ✅

Libraries/LibWeb/DOM/Document.cpp

@@ -592,6 +592,7 @@ void Document::visit_edges(Cell::Visitor& visitor)
     visitor.visit(m_top_layer_pending_removals);
     visitor.visit(m_showing_auto_popover_list);
     visitor.visit(m_showing_hint_popover_list);
+    visitor.visit(m_popover_pointerdown_target);
     visitor.visit(m_console_client);
     visitor.visit(m_editing_host_manager);
     visitor.visit(m_local_storage_holder);
@@ -6117,6 +6118,23 @@ void Document::process_top_layer_removals()
     }
 }
 
+// https://html.spec.whatwg.org/multipage/popover.html#topmost-auto-popover
+GC::Ptr<HTML::HTMLElement> Document::topmost_auto_or_hint_popover()
+{
+    // To find the topmost auto or hint popover given a Document document, perform the following steps. They return an HTML element or null.
+
+    // 1. If document's showing hint popover list is not empty, then return document's showing hint popover list's last element.
+    if (!m_showing_hint_popover_list.is_empty())
+        return m_showing_hint_popover_list.last();
+
+    // 2. If document's showing auto popover list is not empty, then return document's showing auto popover list's last element.
+    if (!m_showing_auto_popover_list.is_empty())
+        return m_showing_auto_popover_list.last();
+
+    // 3. Return null.
+    return {};
+}
+
 void Document::set_needs_to_refresh_scroll_state(bool b)
 {
     if (auto* paintable = this->paintable())