Defer the real work in updateCompositingLayers until it's really needed.

Source/core/rendering/CompositedLayerMapping.cpp

Index: Source/core/rendering/CompositedLayerMapping.cpp
diff --git a/Source/core/rendering/CompositedLayerMapping.cpp b/Source/core/rendering/CompositedLayerMapping.cpp
index 3293820e1628fa3350db6b201331d6459b32182b..7921d1a883c4b0ca236041f411a30cfe0bcfacab 100644
--- a/Source/core/rendering/CompositedLayerMapping.cpp
+++ b/Source/core/rendering/CompositedLayerMapping.cpp
@@ -751,6 +751,8 @@ void CompositedLayerMapping::updateGraphicsLayerGeometry()
         }
     }
 
+    m_owningLayer->positionOverflowControls();
+
     // If this layer was created just for clipping or to apply perspective, it doesn't need its own backing store.
     setRequiresOwnBackingStore(compositor()->requiresOwnBackingStore(m_owningLayer, compAncestor));