Currently, WebWorkerFetchContext::SetTerminateSyncLoadEvent() is called from ThreadedMessagingProxyBase::InitializeWorkerThread(). This works well for dedicated workers and worklets, but doesn't for shared workers and service workers because they don't use ThreadedMessagingProxyBase.

We should call the function for shared workers and service workers from somewhere to ensure worker termination during sync resource requests (i.e., importScripts() and SyncXHR).