[content-visibility] Fix dynamic-change-paint-fully-obscuring-child-001.html

https://bugs.webkit.org/show_bug.cgi?id=247617

Reviewed by Simon Fraser.

A child can't obscure a parent element that should skip its contents
due to hidden content-visibility, so adjust foregroundIsKnownToBeOpaqueInRect
to that.

* LayoutTests/TestExpectations:
* Source/WebCore/rendering/RenderBox.cpp:
(WebCore::RenderBox::foregroundIsKnownToBeOpaqueInRect const):

Canonical link: https://commits.webkit.org/257549@main

Author: rwlbuis

LayoutTests/TestExpectations

@@ -4836,7 +4836,6 @@ imported/w3c/web-platform-tests/css/css-contain/content-visibility/content-visib
 imported/w3c/web-platform-tests/css/css-contain/content-visibility/content-visibility-with-top-layer-004.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-contain/content-visibility/content-visibility-with-top-layer-hide-after-addition.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-contain/content-visibility/content-visibility-video.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-contain/content-visibility/dynamic-change-paint-fully-obscuring-child-001.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-contain/counter-scoping-001.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-contain/counter-scoping-002.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-contain/quote-scoping-001.html [ ImageOnlyFailure ]

Source/WebCore/rendering/RenderBox.cpp

@@ -1728,6 +1728,9 @@ bool RenderBox::foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, u
     if (!maxDepthToTest)
         return false;
 
+    if (shouldSkipContent())
+        return false;
+
     for (auto& childBox : childrenOfType<RenderBox>(*this)) {
         if (!isCandidateForOpaquenessTest(childBox))
             continue;