WPT import https://crrev.com/c/1182607 introduced new failures in external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0:

List of new failures:
[ Mac ] external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/fieldset-flexbox.html new failing tests: https://crrev.com/c/1182607/4/third_party/WebKit/LayoutTests/platform/mac/external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/fieldset-flexbox-expected.txt
[ Win ] external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/fieldset-flexbox.html new failing tests: https://crrev.com/c/1182607/4/third_party/WebKit/LayoutTests/platform/win/external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/fieldset-flexbox-expected.txt
external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/min-inline-size.html new failing tests: https://crrev.com/c/1182607/4/third_party/WebKit/LayoutTests/external/wpt/html/rendering/non-replaced-elements/the-fieldset-element-0/min-inline-size-expected.txt

This import contains upstream changes from 0caf88f800d70c086bf481e009abb29affb49a40 to 87329a1500b1aea8f9cf28b40afb08491e25a5c7:
HTML: document.open() and tasks (#10818): https://github.com/web-platform-tests/wpt/commit/87329a1500b1aea8f9cf28b40afb08491e25a5c7 [affecting this directory]
Meta: remove emilio as XHR reviewer: https://github.com/web-platform-tests/wpt/commit/35ef190b37f437ebf44422f2e3aa5d426f98dd82
HTML: fieldset should have min-inline-size: min-content: https://github.com/web-platform-tests/wpt/commit/a150d010d5771afd9d11fcaf08e457d29b1bf48a [affecting this directory]
Fieldset should support CSS Flexbox: https://github.com/web-platform-tests/wpt/commit/d5b9b8c42ac0adf5f37afefa5b7da845fc24e5b2 [affecting this directory]