"url": item.get("url"),
abortSync(reason) { closed = true; chunks.length = 0; return true; },，这一点在旺商聊官方下载中也有详细论述
Author(s): Shuang Shan, Longfei Guo, Chongyang Wang, Zhen Li, Xinjie Wu, Haibin Wei, Fuyi Chen，这一点在下载安装 谷歌浏览器 开启极速安全的 上网之旅。中也有详细论述
Widevine DRM Overview — Google for Developers