REGRESSION(r286828?): [ Win EWS ] fast/css/contain-invalidate-if-disabled.html is a constant failure

[Robert Jenner]

fast/css/contain-invalidate-if-disabled.html

is a constant text failure on Windows. It is also slowing down Windows EWS. 

HISTORY:
https://results.webkit.org/?suite=layout-tests&test=fast%2Fcss%2Fcontain-invalidate-if-disabled.html&version_name=Win10

DIFF URL:
https://build.webkit.org/results/Apple-Win-10-Release-Tests/r287919%20(3970)/fast/css/contain-invalidate-if-disabled-pretty-diff.html

DIFF TEXT:
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
-PASS 'contain' in document.documentElement.style is false
-PASS 'contain' in getComputedStyle(document.documentElement) is false
-PASS getComputedStyle(document.getElementById('target')).getPropertyValue('contain') == '' is true
-PASS CSS.supports('contain: paint') is false
-PASS CSS.supports('contain: inherit') is false
+FAIL 'contain' in document.documentElement.style should be false. Was true.
+FAIL 'contain' in getComputedStyle(document.documentElement) should be false. Was true.
+FAIL getComputedStyle(document.getElementById('target')).getPropertyValue('contain') == '' should be true. Was false.
+FAIL CSS.supports('contain: paint') should be false. Was true.
+FAIL CSS.supports('contain: inherit') should be false. Was true.
 PASS successfullyParsed is true
+Some tests failed.

[Robert Jenner]

Marked test as [ Failure ] to speed up Windows EWS:

https://trac.webkit.org/changeset/287935/webkit

[Radar WebKit Bug Importer]

<rdar://problem/87469583>

[Robert Jenner]

This appears to have regressed with this change: 

https://trac.webkit.org/changeset/286828/webkit

[Rob Buis]

Created attachment 457529 [details]
Patch

[Rob Buis]

Created attachment 457533 [details]
Patch