Improve the compositing reasons when squashing fails

Source/core/rendering/compositing/CompositingLayerAssigner.h

Index: Source/core/rendering/compositing/CompositingLayerAssigner.h
diff --git a/Source/core/rendering/compositing/CompositingLayerAssigner.h b/Source/core/rendering/compositing/CompositingLayerAssigner.h
index 0cfb1112fdc6e73fce5eead742a6a1f79ff65a90..ccc283d3e2048bea9c2af9d7f6ec8457aa8255e9 100644
--- a/Source/core/rendering/compositing/CompositingLayerAssigner.h
+++ b/Source/core/rendering/compositing/CompositingLayerAssigner.h
@@ -79,7 +79,7 @@ private:
 
     void assignLayersToBackingsInternal(RenderLayer*, SquashingState&, bool& layersChanged, Vector<RenderLayer*>& layersNeedingRepaint);
     void assignLayersToBackingsForReflectionLayer(RenderLayer* reflectionLayer, bool& layersChanged, Vector<RenderLayer*>& layersNeedingRepaint);
-    bool canSquashIntoCurrentSquashingOwner(const RenderLayer*, const SquashingState&);
+    CompositingReasons getReasonsPreventingSquashing(const RenderLayer*, const SquashingState&);
     bool squashingWouldExceedSparsityTolerance(const RenderLayer* candidate, const SquashingState&);
     bool updateSquashingAssignment(RenderLayer*, SquashingState&, CompositingStateTransitionType, Vector<RenderLayer*>& layersNeedingRepaint);
     bool needsOwnBacking(const RenderLayer*) const;