LibWeb: Make PaintableBox::enclosing_stacking_context() cheaper

No need to call the expensive establishes_stacking_context() here, as
we've already built the stacking context tree and can simply test for
the presence of existing stacking contexts.

1 files changed, 2 insertions, 4 deletions

diff --git a/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp b/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
index a4c65f1b3e..e0685a5b07 100644
--- a/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
+++ b/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
@@ -86,10 +86,8 @@ Painting::StackingContext* PaintableBox::enclosing_stacking_context()
         if (!is<Layout::Box>(ancestor))
             continue;
         auto& ancestor_box = static_cast<Layout::Box&>(const_cast<Layout::NodeWithStyle&>(*ancestor));
-        if (!ancestor_box.establishes_stacking_context())
-            continue;
-        VERIFY(ancestor_box.paint_box()->stacking_context());
-        return const_cast<StackingContext*>(ancestor_box.paint_box()->stacking_context());
+        if (auto* ancestor_paint_box = ancestor_box.paint_box(); ancestor_paint_box && ancestor_paint_box->stacking_context())
+            return const_cast<StackingContext*>(ancestor_paint_box->stacking_context());
     }
     // We should always reach the Layout::InitialContainingBlock stacking context.
     VERIFY_NOT_REACHED();