Trigger extra GraphicsLayerGeometryUpdate for squashing if we reset compositedBounds on squashed la…

Source/core/rendering/compositing/CompositedLayerMapping.cpp

Index: Source/core/rendering/compositing/CompositedLayerMapping.cpp
diff --git a/Source/core/rendering/compositing/CompositedLayerMapping.cpp b/Source/core/rendering/compositing/CompositedLayerMapping.cpp
index 1997accd403e335080362befcb932f53bcb2f9ff..07227db84d7eb5be0c8c1fbba4492210d9a37472 100644
--- a/Source/core/rendering/compositing/CompositedLayerMapping.cpp
+++ b/Source/core/rendering/compositing/CompositedLayerMapping.cpp
@@ -2059,6 +2059,7 @@ bool CompositedLayerMapping::updateSquashingLayerAssignment(RenderLayer* layer,
             updatedAssignment = true;
         }
         m_squashedLayers[nextSquashedLayerIndex] = paintInfo;
+        m_needToUpdateGeometry = true;
     } else {
         m_squashedLayers.append(paintInfo);
         updatedAssignment = true;