Remove stale platform-specific expectations

LayoutTests/platform/mac/virtual/gpu/compositing/overflow/opt-unclipped-descendants-into-composited-scrolling-expected.txt

Index: LayoutTests/platform/mac/virtual/gpu/compositing/overflow/opt-unclipped-descendants-into-composited-scrolling-expected.txt
diff --git a/LayoutTests/platform/mac/virtual/gpu/compositing/overflow/opt-unclipped-descendants-into-composited-scrolling-expected.txt b/LayoutTests/platform/mac/virtual/gpu/compositing/overflow/opt-unclipped-descendants-into-composited-scrolling-expected.txt
deleted file mode 100644
index cd63db05bdc97c6057e5c40a9dd9aa5ebc59ea93..0000000000000000000000000000000000000000
--- a/LayoutTests/platform/mac/virtual/gpu/compositing/overflow/opt-unclipped-descendants-into-composited-scrolling-expected.txt
+++ /dev/null
@@ -1,55 +0,0 @@
-This test ensures that a stacking context overflow-scroll div's unclipped descendant gets its own composited layer, which is correctly parented under the overflow-div's composited layer.
-
-(GraphicsLayer
-  (bounds 1496.00 585.00)
-  (children 1
-    (GraphicsLayer
-      (bounds 1496.00 585.00)
-      (contentsOpaque 1)
-      (drawsContent 1)
-      (children 1
-        (GraphicsLayer
-          (position 28.00 20.00)
-          (bounds 202.00 202.00)
-          (drawsContent 1)
-          (children 4
-            (GraphicsLayer
-              (position 1.00 1.00)
-              (bounds 185.00 185.00)
-              (children 1
-                (GraphicsLayer
-                  (bounds 190.00 185.00)
-                  (drawsContent 1)
-                  (children 1
-                    (GraphicsLayer
-                      (position 10.00 139.00)
-                      (bounds 180.00 90.00)
-                      (contentsOpaque 1)
-                      (drawsContent 1)
-                      (backgroundColor #808080)
-                    )
-                  )
-                )
-              )
-            )
-            (GraphicsLayer
-              (position 1.00 186.00)
-              (bounds 185.00 15.00)
-            )
-            (GraphicsLayer
-              (position 186.00 1.00)
-              (bounds 15.00 185.00)
-            )
-            (GraphicsLayer
-              (position 186.00 186.00)
-              (bounds 15.00 15.00)
-              (drawsContent 1)
-            )
-          )
-        )
-      )
-    )
-  )
-)
-
-