Implement redirect() API for Fetch Response

LayoutTests/http/tests/fetch/resources/fetch-test-helpers.js

 if ('ServiceWorkerGlobalScope' in self &&
     self instanceof ServiceWorkerGlobalScope) {
   // ServiceWorker case
   importScripts('/serviceworker/resources/worker-testharness.js');
   importScripts('/serviceworker/resources/test-helpers.js');
   importScripts('/serviceworker/resources/fetch-test-options.js');
 } else if (self.importScripts) {
   // Other workers cases
   importScripts('/resources/testharness.js');
   importScripts('/serviceworker/resources/test-helpers.js');
@@ skipping 164 matching lines @@
 var VALID_REASON_PHRASE = [
   '\t', ' ', '"', '(', ')', ',', '/', ':', ';', '<', '=', '>', '?', '@', '[',
   '\\', ']', '{', '}',
   '!', '#', '$', '%', '&', '\'', '*', '+', '-', '.', '^', '_', '`', '|', '~',
   // non-CHAR
   '\x80', '\xff',
   // Valid strings.
   '', '0123456789', '404 Not Found', 'HTTP/1.1 404 Not Found', 'AZ\u00ffaz',
   'x'.repeat(100000)];
 
+var INVALID_URLS =
+  ['http://',
+   'https://',
+   'http://ex%00ample.com',
+   'http://ex%0dample.com',
+   'http://ex%0aample.com',
+   'http://ex%08ample.com',
+   'http://ex\x00ample.com'];
+
 function size(headers) {
   var count = 0;
   for (var header of headers) {
     ++count;
   }
   return count;
 }
 
 function testBlockMixedContent(mode) {
   promise_test(function(t) {
@@ skipping 52 matching lines @@
                 function() {
                   if (mode !== 'same-origin') {
                     assert_unreached(
                       'Test 5: Cross-origin HTTPS request must success: ' +
                       'mode = ' + mode);
                   }
                 });
           });
     }, 'Block fetch() as mixed content (' + mode + ')');
 }