use raf to impl a more accurate timer and replay events async

src/replay/timer.ts

@@ -0,0 +1,17 @@
+const FRAME_MS = 16;
+
+function later(cb: () => void, delayMs: number) {
+  const now = performance.now();
+
+  function check(step: number) {
+    if (step - now > delayMs - FRAME_MS) {
+      cb();
+    } else {
+      requestAnimationFrame(check);
+    }
+  }
+
+  requestAnimationFrame(check);
+}
+
+export default later;