CONSOLE WARNING: line 9: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
CONSOLE ERROR: line 12: Failed to load http://web-platform.test:8001/xhr/resources/pass.txt?pipe=header(Cache-Control,no-store)|header(Content-Type,text/plain): No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.
