call getUserMedia wait long time

[tony sun]

Chrome Version: 70

Description:

when call getUserMedia in chrome 70, wait long time to get user media stream, the whole process  is about spending 2 minutes.  it is not often happen。

code：

    navigator.mediaDevices

     .getUserMedia(this.constraints)

     .then(function(stream) {

       self.getUserMediaSuccess(stream);

     })

     .catch(error => {

       self.onGetUserMediaError(error);

     });

what‘s reason?  is it chrome bug?

thanks