Drop background color optimization for composited layers

LayoutTests/compositing/rtl/rtl-relative-expected.txt

Index: LayoutTests/compositing/rtl/rtl-relative-expected.txt
diff --git a/LayoutTests/compositing/rtl/rtl-relative-expected.txt b/LayoutTests/compositing/rtl/rtl-relative-expected.txt
index 178263b0173c45ffbf4a0737590ef4023d0b9457..30c536d91d523d8e9e37698e410ecfc7b241c53a 100644
--- a/LayoutTests/compositing/rtl/rtl-relative-expected.txt
+++ b/LayoutTests/compositing/rtl/rtl-relative-expected.txt
@@ -10,6 +10,8 @@
           (position 642.00 58.00)
           (bounds 100.00 100.00)
           (contentsOpaque 1)
+          (drawsContent 1)
+          (backgroundColor #008000)
         )
       )
     )