In order for XHR2 timeouts to work, the platform's ResourceRequest implementation needs to handle setTimeoutInterval / m_timeoutInterval like the CF implementation.
For more info, see bug 94796, where it was added for the soup backend.
Implementation was added when bug 74802 landed in r132252.
I skipped the tests on Qt instead of marking them as failing tests, because
they slowed down the testing with 3 minutes (~17%) - https://trac.webkit.org/changeset/132497
According to this comment https://bugs.webkit.org/show_bug.cgi?id=74802#c50 and the fact it was implemented in Qt and chromium closed. Are we left with only AppleWin and Blackberry?