Don't squash layers that have a clip or overflow clip.

LayoutTests/virtual/softwarecompositing/geometry/limit-layer-bounds-clipping-ancestor-expected.txt

Index: LayoutTests/virtual/softwarecompositing/geometry/limit-layer-bounds-clipping-ancestor-expected.txt
diff --git a/LayoutTests/virtual/softwarecompositing/geometry/limit-layer-bounds-clipping-ancestor-expected.txt b/LayoutTests/virtual/softwarecompositing/geometry/limit-layer-bounds-clipping-ancestor-expected.txt
deleted file mode 100644
index f24777c68171760430859a1cb313eaaf8440f664..0000000000000000000000000000000000000000
--- a/LayoutTests/virtual/softwarecompositing/geometry/limit-layer-bounds-clipping-ancestor-expected.txt
+++ /dev/null
@@ -1,49 +0,0 @@
-top
-
-middlebottom
-top
-
-middlebottom
-(GraphicsLayer
-  (bounds 785.00 2618.00)
-  (children 1
-    (GraphicsLayer
-      (bounds 785.00 2618.00)
-      (contentsOpaque 1)
-      (drawsContent 1)
-      (children 2
-        (GraphicsLayer
-          (children 2
-            (GraphicsLayer
-              (position 21.00 21.00)
-              (bounds 100.00 100.00)
-            )
-            (GraphicsLayer
-              (position 18.00 10.00)
-              (bounds 220.00 220.00)
-              (drawsContent 1)
-            )
-          )
-        )
-        (GraphicsLayer
-          (position 28.00 20.00)
-          (bounds 200.00 200.00)
-          (children 2
-            (GraphicsLayer
-              (bounds 110.00 200.00)
-              (contentsOpaque 1)
-              (drawsContent 1)
-              (backgroundColor #008000)
-            )
-            (GraphicsLayer
-              (position 5.00 145.00)
-              (bounds 144.00 24.00)
-              (drawsContent 1)
-            )
-          )
-        )
-      )
-    )
-  )
-)
-