Summary:
Corresponding iOS PR: #12275
Respect the withCredentials XMLHttpRequest flag for sending cookies with requests. This can reduce payload sizes where large cookies are set for domains.
This should fix#5347.
This is a breaking change because it alters the default behavior of XHR. Prior to this change, XHR would send cookies by default. After this change, by default, XHR does not send cookies which is consistent with the default behavior of XHR on web for cross-site requests. Developers can restore the previous behavior by passing `true` for XHR's `withCredentials` argument.
**Test plan (required)**
Verified in a test app that XHR works properly when specifying `withCredentials` as `true`, `false`, and `undefined`. Also, my team uses this change in our app.
Adam Comella
Microsoft Corp.
Closes https://github.com/facebook/react-native/pull/12276
Differential Revision: D4673646
Pulled By: ericvicenti
fbshipit-source-id: 924c230c9df72071b3cf9151c3ac201905ac28a5
e544563bd2