Fetch: Fix 'body' processing in RequestInit.

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

Index: third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html b/third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html
index 7622777cb22bc17419105a601acd8018002a32a3..5fe86f908e0702c5dcb683888fe8202b690421dc 100644
--- a/third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html
+++ b/third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html
@@ -12,6 +12,16 @@ var c = new PasswordCredential({
 });
 
 promise_test(_ => {
+    var r = new Request('/', { credentials: c, body: 'this is a body', method: 'POST' });
+    return r.text().then(t => assert_equals(t, ""));
+}, "Body ignored in presence of a PasswordCredential");
+
+promise_test(_ => {
+    var r = new Request('/', { credentials: 'include', body: 'this is a body', method: 'POST' });
+    return r.text().then(t => assert_equals(t, "this is a body"));
+}, "Body present if 'credentials' is not a PasswordCredential");
+
+promise_test(_ => {
     var r = new Request('/', { credentials: c, method: 'POST' });
     var clone = r.clone();
     assert_equals(r.credentials, "password");