Prepare RenderLayer/RenderLayerBacking for RenderSVGModelObject support: Suppress all paint phases except PaintPhase::Foreground for SVG primitives.
Created attachment 451014 [details] Patch, v1
Created attachment 451030 [details] Patch, v2
Created attachment 451038 [details] Patch, v3
Committed r289205 (246891@trunk): <https://commits.webkit.org/246891@trunk>
<rdar://problem/88564992>