peerconn的信令是通过post 消息到自己的信令线程消息来处理的PeerConnectionMessageHandler 是具体的处理器G:\CDN\rtcCli\m98\src\pc\peer_connection_message_handler.h Machinery for handling messages posted to oneself PeerConnectionMessageHandler 明确服务于 signaling_thread_ private:rtc::Thread*