Intermittent failure in /css-text-3_dev/html/seg-break-transformation-004.htm

[jdm]

  ▶ Unexpected subtest result in /css-text-3_dev/html/seg-break-transformation-004.htm:
  │ FAIL [expected PASS] multiple linebreaks + spaces \uff12\uff14\ufffd\ufffd\ufffd
  │   → assert_equals: expected 73 but got 79
  │ 
  │ @http://web-platform.test:8000/css-text-3_dev/html/seg-break-transformation-004.htm:87:1
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1403:20
  │ test@http://web-platform.test:8000/resources/testharness.js:501:9
  └ @http://web-platform.test:8000/css-text-3_dev/html/seg-break-transformation-004.htm:86:1