@TargetApi(Build.VERSION_CODES.LOLLIPOP)
        @Override
        public void onPermissionRequest(PermissionRequest request) {
            if (webChromeClient != null) {
                webChromeClient.onPermissionRequest(request);
            } else {
                super.onPermissionRequest(request);
            }
        }
This method can be called in any thread, and if it is not called in the main thread,
it will be automatically distributed to the main thread.

@param url
@param additionalHttpHeaders
app/src/main/java/com/example/jingbin/webviewstudy/view/WVJBWebView.java