chromium/third_party/blink/web_tests/editing/spelling/spellcheck-paste-disabled.html

<!doctype html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../assert_selection.js"></script>
<script src="spellcheck_test.js"></script>

<script>
spellcheck_test(
    '<div contenteditable spellcheck="false">|</div contenteditable>',
    document => {
      document.getSelection().setClipboardData('zz apple.');
      document.execCommand('paste');
    },
    '<div contenteditable spellcheck="false">zz apple.</div>',
    'No spellchecking when pasting into spellcheck=false.');
</script>