fn traverse_element<'dom>(
element: ServoThreadSafeLayoutNode<'dom>,
context: &LayoutContext<'_>,
handler: &mut impl TraversalHandler<'dom>,
)fn traverse_element<'dom>(
element: ServoThreadSafeLayoutNode<'dom>,
context: &LayoutContext<'_>,
handler: &mut impl TraversalHandler<'dom>,
)