Convert additive-transform-animations to ref-test

LayoutTests/animations/additive-transform-animations.html

Index: LayoutTests/animations/additive-transform-animations.html
diff --git a/LayoutTests/animations/additive-transform-animations.html b/LayoutTests/animations/additive-transform-animations.html
index 8762512cbaa13c332dca3249ec6a8d138fb23b95..b19cc9d5dd5f53848905db60fd15f552f119c7d7 100644
--- a/LayoutTests/animations/additive-transform-animations.html
+++ b/LayoutTests/animations/additive-transform-animations.html
@@ -17,10 +17,6 @@
         from { -webkit-transform: rotate(0deg) translate(-100px, 0); }
         to   { -webkit-transform: rotate(180deg) translate(300px, 0); }
     }
-
-    #result {
-      opacity: 0; /* hide in pixel result */
-    }
   </style>
   <script src="resources/animation-test-helpers.js" type="text/javascript"></script>
   <script type="text/javascript">