Function step

vm/ByteCodeTranslator/src/javascript/browser_bridge.js:1985–2020

()

        return;
      }
      function step() {
        // Race rAF against a setTimeout fallback. Headless Chromium throttles
        // and ultimately STOPS firing requestAnimationFrame when the page idles
        // (no compositing) -- which happens right after a form transition
        // completes and the worker's EDT parks on __cn1_wait_for_ui_settle__,
        // leaving nothing to drive a frame. Without the fallback this runFrame
        // chain never resolves, the host never replies, and the EDT parks
        // forever (the SlideHorizontalTransitionTest wall). The fallback
        // guarantees forward progress; when rAF is healthy it wins the race so
        // steady-state timing is unchanged.
        var advanced = false;
        function tick() {
          if (advanced) {
            return;
          }
          advanced = true;
          var idx = pendingFrameTicks.indexOf(tick);
          if (idx >= 0) {
            pendingFrameTicks.splice(idx, 1);
          }
          remaining--;
          if (remaining <= 0) {
            resolve();
            return;
          }
          step();
        }
        // Hidden/headless pages throttle BOTH rAF (stops entirely) and the
        // setTimeout fallback (intensive wake-up batching), so register the
        // tick for the external __cn1NudgeVm driver too -- a CDP-driven
        // nudge resolves pending frame waits within its interval instead of
        // stalling each settle for seconds.
        pendingFrameTicks.push(tick);
        raf(tick);
        setTimeout(tick, 32);
      }
      step();
    });
  }