Function metrics::set_metric

pub(crate) fn set_metric<U: ProgressiveWebMetric>(
    pwm: &U,
    metadata: Option<TimerMetadata>,
    metric_type: ProgressiveWebMetricType,
    category: ProfilerCategory,
    attr: &Cell<Option<u64>>,
    metric_time: Option<u64>,
    url: &ServoUrl
)