[setrequestheader-content-type.htm]
  type: testharness
  [XMLHttpRequest: setRequestHeader() - Content-Type header ()]
    expected: FAIL

  [XMLHttpRequest: setRequestHeader() - Content-Type header ( )]
    expected: FAIL

  [XMLHttpRequest: setRequestHeader() - Content-Type header (null)]
    expected: FAIL

  [XMLHttpRequest: setRequestHeader() - Content-Type header (undefined)]
    expected: FAIL

