Quanta Clock is off by a factor of 1000 in web browsers

[vargad]

window.performance.now() return milliseconds. As Instant is in nanoseconds, it needs to be multiplied by 1.000.000 not 1.000.

Example to demonstrate the problem:

#[wasm_bindgen]
pub struct TestQuanta
{
    last_time: quanta::Instant
}

#[wasm_bindgen]
impl TestQuanta
{
    #[wasm_bindgen(constructor)]
    pub fn new() -> Self
    {
        Self{last_time: quanta::Instant::now()}
    }

    #[wasm_bindgen(method)]
    pub fn time_since_last_call(&mut self) -> f64
    {
        let now = quanta::Instant::now();
        let elapsed = now.duration_since(self.last_time);
        self.last_time = now;
        elapsed.as_millis() as f64
    }
}

let test_quanta = new TestQuanta();
setInterval(() => console.log(`elapsed: ${test_quanta.time_since_last_call()}ms`), 3000);

Expected: log something around 3000ms, as interval is called every 3000ms.