here is some information I got map error pc ffffdafc from: WebCore::ScrollableArea::hasOverlayScrollbars() const Source/WebCore/platform/ScrollableArea.cpp from: WebCore::RenderLayerBacking::requiresHorizontalScrollbarLayer() const Source/WebCore/rendering/RenderLayerBacking.cpp from: WebCore::RenderLayerBacking::updateGraphicsLayerConfiguration() Source/WebCore/rendering/RenderLayerBacking.cpp from: WebCore::RenderLayerCompositor::rebuildCompositingLayerTree(WebCore::RenderLayer*, WebCore::CompositingState const&, WTF::Vector<WebCore::GraphicsLayer*, 0u>&) Source/WebCore/rendering/RenderLayerCompositor.cpp Thanks!