LayoutTests/imported/w3c/web-platform-tests/service-workers/service-worker/resources/mime-sniffing-worker.js - WebKit - Git at Google

 self.addEventListener('fetch', function(event) {
     var res = new Response('<!DOCTYPE html>\n<h1 id=\'testid\'>test</h1>');
     res.headers.delete('content-type');
     event.respondWith(res);
   });
	self.addEventListener('fetch', function(event) {
	var res = new Response('<!DOCTYPE html>\n<h1 id=\'testid\'>test</h1>');
	res.headers.delete('content-type');
	event.respondWith(res);
	});