Fix a 'promise_test' bug in 'http/tests/credentialmanager/passwordcredential-fetch.html'.

BUG=662172

Review-Url: https://codereview.chromium.org/2482443002
Cr-Commit-Position: refs/heads/master@{#430243}

third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch-expected.txt

-This is a testharness.js-based test.
-PASS Body ignored in presence of a PasswordCredential 
-PASS Body present if 'credentials' is not a PasswordCredential 
-PASS Creating/cloning a 'Request' does not expose the credential. 
-FAIL Creating a 'Request' throws in various ways. assert_not_equals: got disallowed value undefined
-PASS Simple Fetch 
-PASS Simple Fetch 
-PASS Fetch with cloned Request 
-PASS Fetch with copied Request 
-PASS Fetch with overridden 'credentials' 
-PASS 'idName' and 'passwordName' 
-PASS 'additionalData': Empty FormData has no effect. 
-PASS 'additionalData': FormData properties are properly injected. 
-PASS 'additionalData': FormData properties are properly injected after assignment. 
-PASS 'additionalData': FormData properties are properly overridden. 
-PASS 'additionalData': Empty URLSearchParams has no effect. 
-PASS 'additionalData': URLSearchParams properties are properly injected. 
-PASS 'additionalData': URLSearchParams properties are properly overridden. 
-PASS 'additionalData': URLSearchParams properties are properly injected (ordering matters). 
-PASS fetch() after get() 
-PASS fetch() after get() with additionalData 
-PASS fetch() after get() with additionalData from DOM 
-Harness: the test ran to completion.
-

third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html

@@ -39,7 +39,7 @@ promise_test(_ => {
     ]);
 }, "Creating/cloning a 'Request' does not expose the credential.");
 
-promise_test(_ => {
+test(_ => {
     assert_throws(new TypeError(), _ => new Request("https://cross-origin.example.test/", { credentials: c, method: 'POST' }));
     assert_throws(new TypeError(), _ => new Request("/", { credentials: c, method: 'GET' }));
     assert_throws(new TypeError(), _ => new Request("/", { credentials: c, method: 'HEAD' }));