Upstream service wrkr "respond with" tests to WPT

third_party/WebKit/LayoutTests/external/wpt/service-workers/service-worker/resources/fetch-event-respond-with-response-body-with-invalid-chunk-worker.js

+'use strict';
+
 self.addEventListener('fetch', event => {
     if (!event.request.url.match(/body-stream-with-invalid-chunk$/))
       return;
     const stream = new ReadableStream({start: controller => {
         // The argument is intentionally a string, not a Uint8Array.
         controller.enqueue('hello');
       }});
     const headers = { 'x-content-type-options': 'nosniff' };
     event.respondWith(new Response(stream, { headers }));
   });