Bug 275803 – [TexMap] Correctly gather damage information for 3D-transformed layers

• Status: RESOLVED
• Resolution: FIXED
• Component: Compositing

[Adrian Perez]

As part of the work in bug #265777 we introduced a mechanism that tries
to skip computing damage regions for 3D-transformed layers and, if one
such layer is detected, invalidate the complete frame. See function
layerRendererStyleHas3DTransformOperation() in RenderLayerBacking.cpp,
and its callsite in RenderLayerBacking::updateAfterDescendants().

This mechanism does not always work as intended, and for example artifacts
can still be seen in https://people.igalia.com/aperez/poster-circle.html
which means the layerRendererStyleHas3DTransformOperation() check is not
completely correct.

Ideally, we would prefer this check to be removed and regions properly
calculated. Otherwise, we should at least make the check work as
intended.

[Radar WebKit Bug Importer]

<rdar://problem/130880776>

[EWS]

Committed 289232@main (d2869dc073cd): <https://commits.webkit.org/289232@main>

Reviewed commits have been landed. Closing PR #39074 and removing active labels.