Use the request URL as the URL of the resources which are fetched ServiceWorker [3/3 blink]

LayoutTests/http/tests/serviceworker/resources/fetch-request-css-base-url-worker.js

+importScripts('test-helpers.js');
+
+var port = undefined;
+
+self.onmessage = function(e) {
+  var message = e.data;
+  if ('port' in message) {
+    port = message.port;
+    port.postMessage({ready: true});
+  }
+};
+
+self.addEventListener('fetch', function(event) {
+    var url = event.request.url;
+    if (url.indexOf('fetch-request-css-base-url-style.css') != -1) {
+      event.respondWith(fetch(
+        get_host_info()['HTTP_REMOTE_ORIGIN'] + base_path() +
+        'fetch-request-css-base-url-style.css',
+        {mode: 'no-cors'}));
+    } else if (url.indexOf('dummy.png') != -1) {
+      port.postMessage({
+          url: event.request.url,
+          referrer: event.request.referrer
+        });
+    }
+  });