Enable universal accelerated overflow scroll

LayoutTests/compositing/overflow/resources/automatically-opt-into-composited-scrolling.css

Index: LayoutTests/compositing/overflow/resources/automatically-opt-into-composited-scrolling.css
diff --git a/LayoutTests/compositing/overflow/resources/automatically-opt-into-composited-scrolling.css b/LayoutTests/compositing/overflow/resources/automatically-opt-into-composited-scrolling.css
deleted file mode 100644
index 82105168d122365f242615f208cba7b8ae7e9782..0000000000000000000000000000000000000000
--- a/LayoutTests/compositing/overflow/resources/automatically-opt-into-composited-scrolling.css
+++ /dev/null
@@ -1,47 +0,0 @@
-.container {
-  width: 200px;
-  height: 200px;
-  overflow: scroll;
-  margin: 20px;
-  border: 1px solid black;
-  background-color: #00FFFF;
-}
-
-.scrolled {
-  width: 180px;
-  height: 30px;
-  margin: 10px;
-  top: 70px;
-  background-color: gray;
-  position: relative;
-}
-
-.positioned {
-  width: 120px;
-  height: 240px;
-  position: absolute;
-}
-
-#secondChild {
-  background-color: #CC9999;
-  top: 50px;
-}
-
-#predecessor {
-  left: 20px;
-  top: 20px;
-  background-color: #990066;
-}
-
-#successor {
-  left: 20px;
-  top: 20px;
-  background-color: #000066;
-}
-
-#normalFlow {
-  width: 180px;
-  height: 30px;
-  margin: 10px;
-  background-color: yellow;
-}