[content-visibility] css/css-contain/content-visibility/content-visib…

…ility-auto-state-changed-removed.html fails sometimes

https://bugs.webkit.org/show_bug.cgi?id=264414

Reviewed by Simon Fraser.

Change timing of checking whether the element to dispatch ContentVisibilityAutoStateChangeEvent to is connected to the
moment we try to dispatch, rather than the time we queue the dispatching task.

* Source/WebCore/dom/ContentVisibilityDocumentState.cpp:
(WebCore::ContentVisibilityDocumentState::checkRelevancyOfContentVisibilityElement const):

Canonical link: https://commits.webkit.org/271293@main

Source/WebCore/dom/ContentVisibilityDocumentState.cpp

@@ -147,11 +147,13 @@ bool ContentVisibilityDocumentState::checkRelevancyOfContentVisibilityElement(El
     auto isSkippedContent = target.isRelevantToUser() ? IsSkippedContent::No : IsSkippedContent::Yes;
     target.invalidateStyle();
     updateAnimations(target, wasSkippedContent, isSkippedContent);
-    if (target.isConnected()) {
-        ContentVisibilityAutoStateChangeEvent::Init init;
-        init.skipped = isSkippedContent == IsSkippedContent::Yes;
-        target.queueTaskToDispatchEvent(TaskSource::DOMManipulation, ContentVisibilityAutoStateChangeEvent::create(eventNames().contentvisibilityautostatechangeEvent, init));
-    }
+    target.queueTaskKeepingThisNodeAlive(TaskSource::DOMManipulation, [&, isSkippedContent] {
+        if (target.isConnected()) {
+            ContentVisibilityAutoStateChangeEvent::Init init;
+            init.skipped = isSkippedContent == IsSkippedContent::Yes;
+            target.dispatchEvent(ContentVisibilityAutoStateChangeEvent::create(eventNames().contentvisibilityautostatechangeEvent, init));
+        }
+    });
     return true;
 }