[ContentChangeObserver] Ignore reconstructed renderers when checking for visibility change

[zalan]

when the renderer is destroyed and reconstructed, the newly created renderer is (mistakenly)considered a visible change.

[zalan]

<rdar://problem/49288174>

[zalan]

Created attachment 366494 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 366494 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=366494&action=review

> Source/WebCore/ChangeLog:11
> +        as "visible change" -> hover.

-> to "thereby triggering"

> Source/WebCore/page/ios/ContentChangeObserver.cpp:321
> +    if (!isConsideredHidden(element))
> +        m_elementsWithDestroyedVisibleRenderer.add(&element);

Maybe add a test for this code path.

> Source/WebCore/page/ios/ContentChangeObserver.cpp:510
> +    auto needsObserving = m_contentChangeObserver.isObservingContentChanges() 
> +        && !m_contentChangeObserver.hasVisibleChangeState()
> +        && !m_contentChangeObserver.visibleRendererWasDestroyed(m_element);

Maybe move into a private function

> Source/WebCore/page/ios/ContentChangeObserver.cpp:512
> +        if (needsObserving)
> +            m_wasHidden = isConsideredHidden(m_element);

Indentation!

[zalan]

Created attachment 366511 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 366511 [details]
Patch

Clearing flags on attachment: 366511

Committed r243752: <https://trac.webkit.org/changeset/243752>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.