LibJS+LibWeb: Use new Cell::Visitor helpers to avoid manual iteration

Author: https://github.com/awesomekling
Commit: 53d0dd4a2e
Pull-request: https://github.com/SerenityOS/serenity/pull/23971
Reviewed-by: https://github.com/trflynn89

Userland/Libraries/LibWeb/ResizeObserver/ResizeObserverEntry.cpp

@@ -68,12 +68,9 @@ void ResizeObserverEntry::visit_edges(JS::Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
     visitor.visit(m_target);
-    for (auto& size : m_content_box_size)
-        visitor.visit(size);
-    for (auto& size : m_border_box_size)
-        visitor.visit(size);
-    for (auto& size : m_device_pixel_content_box_size)
-        visitor.visit(size);
+    visitor.visit(m_content_box_size);
+    visitor.visit(m_border_box_size);
+    visitor.visit(m_device_pixel_content_box_size);
     visitor.visit(m_content_rect);
 }