Rename fetch layout tests.

LayoutTests/http/tests/fetch/resources/fetch-access-control-worker.js

-importScripts('fetch-test-options.js');
-importScripts('fetch-access-control-util.js');
-
-var port = undefined;
-var isTestTargetFetch = false;
-
-self.onmessage = function(e) {
-  var message = e.data;
-  if ('port' in message) {
-    port = message.port;
-  } else if (message.msg === 'START TEST CASE') {
-    isTestTargetFetch = true;
-    port.postMessage({msg: 'READY'});
-  }
-};
-
-self.addEventListener('fetch', function(event) {
-    if (!isTestTargetFetch) {
-      // Don't handle the event when it is not the test target fetch such as a
-      // redirected fetch or for the iframe html.
-      return;
-    }
-    isTestTargetFetch = false;
-
-    event.respondWith(
-      doFetch(event.request)
-        .then(function(message) {
-            var response = message.response;
-            message.response = undefined;
-            // Send the result to fetch-access-control-util.js.
-            port.postMessage(message);
-            return response;
-          })
-        .catch(function(message) {
-            port.postMessage(message);
-            return Promise.reject();
-          })
-      );
-  });