Rename fetch layout tests.

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

 if (self.importScripts) {
   importScripts('/resources/testharness.js');
   importScripts('/resources/testharness-helpers.js');
   importScripts('/serviceworker/resources/test-helpers.js');
-  importScripts('../resources/fetch-test-options.js');
+  importScripts('/fetch/resources/fetch-test-options.js');
 }
 
 function getContentType(headers) {
   var content_type = '';
   for (var header of headers) {
     if (header[0] == 'content-type')
       content_type = header[1];
   }
   return content_type;
 }
@@ skipping 193 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 + ')');
 }