pub fn find_character_offset_in_fragment_descendants(
node: &ServoThreadSafeLayoutNode<'_>,
stacking_context_tree: &StackingContextTree,
point_in_viewport: Point2D<Au, CSSPixel>,
) -> Option<usize>pub fn find_character_offset_in_fragment_descendants(
node: &ServoThreadSafeLayoutNode<'_>,
stacking_context_tree: &StackingContextTree,
point_in_viewport: Point2D<Au, CSSPixel>,
) -> Option<usize>