Function handle_get_stylesheet_style 

pub(crate) fn handle_get_stylesheet_style(
    cx: &mut JSContext,
    state: &DevtoolsState,
    documents: &DocumentCollection,
    pipeline: PipelineId,
    node_id: &str,
    matched_rule: MatchedRule,
    reply: GenericSender<Option<Vec<NodeStyle>>>,
)