simonla

It looks like we will only have one request at same time So we can hold one `FrameCallback` instance safely [animator.cc](https://github.com/flutter/engine/blob/main/shell/common/animator.cc#L214): ```cpp if (!pending_frame_semaphore_.TryWait()) { // Multiple calls to Animator::RequestFrame...

> Validations Fail. @jason-simmons help~ 👀

@jason-simmons Got test-exempt and two approver. Would you mind helping me add the autosubmit tag again？

每天早上要开电脑重连，有解吗