Intermittent failure in /css/css-align/blocks/align-content-block-002.html #37361
Description
https://github.com/servo/servo/actions/runs/15541185119/job/43752558209
▶ OK /css/css-align/blocks/align-content-block-002.html
│ ▶ FAIL [expected PASS] .test 1: start
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: start" title="start">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">START</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 4: baseline
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: baseline" title="baseline">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">BASELINE</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 6: flex-start
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: flex-start" title="flex-start">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">FLEX-START</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 8: unsafe start
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: unsafe start" title="unsafe start">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">UNSAFE START</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 11: safe start
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: safe start" title="safe start">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">SAFE START</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 15: space-between
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: space-between" title="space-between">
│ │ → <div class="in-flow" data-offset-y="15"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">SPACE-BETWEEN</span>
│ │ → <span class="abspos" data-offset-y="0">ABS</span>
│ │ → <span class="relpos" data-offset-y="0">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected 0 but got -1
│ │ FAIL [expected PASS] .test 17: normal
│ │ → assert_equals:
│ │ → <div class="test" style="align-content: normal" title="normal">
│ │ → <div class="in-flow" data-offset-y="10"></div>
│ │ → <div class="in-flow">
│ │ → <span class="label">NORMAL</span>
│ │ → <span class="abspos" data-offset-y="-5">ABS</span>
│ │ → <span class="relpos" data-offset-y="-5">REL</span>
│ │ → <div class="overflow">OVERFLOW</div>
│ │ → </div>
│ │ → </div>
│ │ → offsetTop expected -5 but got -6
│ │
│ │ assert_tolerance@http://web-platform.test:8000/resources/check-layout-th.js:24:22
│ │ checkExpectedValues@http://web-platform.test:8000/resources/check-layout-th.js:87:25
│ │ checkSubtreeExpectedValues@http://web-platform.test:8000/resources/check-layout-th.js:7:44
│ │ checkSubtreeExpectedValues/<@http://web-platform.test:8000/resources/check-layout-th.js:9:26
│ │ checkSubtreeExpectedValues@http://web-platform.test:8000/resources/check-layout-th.js:8:29
│ │ checkSubtreeExpectedValues/<@http://web-platform.test:8000/resources/check-layout-th.js:9:26
│ │ checkSubtreeExpectedValues@http://web-platform.test:8000/resources/check-layout-th.js:8:29
│ │ window.checkLayout/</<@http://web-platform.test:8000/resources/check-layout-th.js:229:34
│ │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:2684:25
│ │ test@http://web-platform.test:8000/resources/testharness.js:633:30
│ │ window.checkLayout/<@http://web-platform.test:8000/resources/check-layout-th.js:222:13
│ │ window.checkLayout@http://web-platform.test:8000/resources/check-layout-th.js:220:29
└ └ onload@http://web-platform.test:8000/css/css-align/blocks/align-content-block-002.html:2:12
Probably the same as #37360