Allow redirects for requests that require preflight.

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/thorough/redirect.js

 if (self.importScripts) {
   importScripts('/fetch/resources/fetch-test-helpers.js');
   importScripts('/fetch/resources/thorough-util.js');
 }
 
 var TEST_TARGETS = [
   // Redirect: same origin -> same origin
   [REDIRECT_URL + encodeURIComponent(BASE_URL) +
    '&mode=same-origin&method=GET',
    [fetchResolved, hasContentLength, hasServerHeader, hasBody, typeBasic],
@@ skipping 172 matching lines @@
    '&mode=cors&credentials=same-origin&method=post&ACAOrigin=*&Status=307',
    [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
    [methodIsPOST]],
   // The 308 redirect response MUST NOT change the method.
   // FIXME: disabled due to https://crbug.com/451938
   // [OTHER_REDIRECT_URL + encodeURIComponent(BASE_URL + 'ACAOrigin=*') +
   //  '&mode=cors&credentials=same-origin&method=post&ACAOrigin=*&Status=308',
   //  [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
   //  [methodIsPOST]],
 
-  // Once CORS preflight flag is set, redirecting to the cross-origin is not
-  // allowed.
+  // Requests that require preflight.
   // Custom method
-  [OTHER_REDIRECT_URL +
+  [OTHER_BASE_URL +

[yhirano, 2016/10/27 06:19:44]

I'm a bit confused: As you are making redirect + CORS w/preflight allowed, I
didn't expect the url change from _REDIRECT_ to _BASE_. Can you explain?

[Jack Bates, 2016/11/03 17:22:03]

My mistake. REDIRECT_URL was incorrectly redirecting the preflight request
(before the request w/preflight).
I thought I needed BASE_URL to properly handle the preflight, however I now see
that REDIRECT_URL does the job.
In the latest CL I updated redirect.php to avoid redirecting the preflight and
reverted BASE_URL back to REDIRECT_URL.

    encodeURIComponent(BASE_URL + 'ACAOrigin=*&ACAMethods=PUT') +
    '&mode=cors&credentials=same-origin&method=PUT&ACAOrigin=*&ACAMethods=PUT',
-   [fetchRejected]],
+   [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
+   [methodIsPUT]],
   // Custom header
-  [OTHER_REDIRECT_URL +
+  [OTHER_BASE_URL +
    encodeURIComponent(
        BASE_URL +
        'ACAOrigin=' + BASE_ORIGIN + '&ACAHeaders=x-serviceworker-test') +
-   '&mode=cors&credentials=same-origin&method=GET&headers=CUSTOM&ACAOrigin=*',
-   [fetchRejected]],
+   '&mode=cors&credentials=same-origin&method=GET&headers=CUSTOM' +
+   '&ACAOrigin=*&ACAHeaders=x-serviceworker-test',
+   [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
+   [methodIsGET, hasCustomHeader]],
 
   // Redirect: other origin -> other origin
   [OTHER_REDIRECT_URL + encodeURIComponent(OTHER_BASE_URL) +
    '&mode=same-origin&method=GET',
    [fetchRejected]],
   [OTHER_REDIRECT_URL + encodeURIComponent(OTHER_BASE_URL) +
    '&mode=cors&credentials=same-origin&method=GET',
    [fetchRejected]],
   [OTHER_REDIRECT_URL + encodeURIComponent(OTHER_BASE_URL) +
    '&mode=cors&credentials=same-origin&method=GET&ACAOrigin=*',
@@ skipping 48 matching lines @@
   //  [methodIsPOST]],
 
   // Server header
   [OTHER_REDIRECT_URL +
    encodeURIComponent(OTHER_BASE_URL +
                       'ACAOrigin=*&ACEHeaders=X-ServiceWorker-ServerHeader') +
    '&mode=cors&credentials=same-origin&method=GET&ACAOrigin=*',
    [fetchResolved, noContentLength, hasServerHeader, hasBody, typeCors],
    [methodIsGET, authCheckNone]],
 
-  // Once CORS preflight flag is set, redirecting to the cross-origin is not
-  // allowed.
+  // Requests that require preflight.
   // Custom method
-  [OTHER_REDIRECT_URL +
+  [OTHER_BASE_URL +
    encodeURIComponent(OTHER_BASE_URL + 'ACAOrigin=*&ACAMethods=PUT') +
    '&mode=cors&credentials=same-origin&method=PUT&ACAOrigin=*&ACAMethods=PUT',
-   [fetchRejected]],
+   [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
+   [methodIsPUT]],
   // Custom header
-  [OTHER_REDIRECT_URL +
+  [OTHER_BASE_URL +
    encodeURIComponent(
      OTHER_BASE_URL +
      'ACAOrigin=' + BASE_ORIGIN + '&ACAHeaders=x-serviceworker-test') +
    '&mode=cors&credentials=same-origin&method=GET&headers=CUSTOM' +
    '&ACAOrigin=' + BASE_ORIGIN + '&ACAHeaders=x-serviceworker-test',
-   [fetchRejected]],
+   [fetchResolved, noContentLength, noServerHeader, hasBody, typeCors],
+   [methodIsGET, hasCustomHeader]],
 ];
 
 if (self.importScripts) {
   executeTests(TEST_TARGETS);
   done();
 }