Convert some repaint tests into ref tests

third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change-expected.html

Index: third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change-expected.html
diff --git a/third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change.html b/third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change-expected.html
similarity index 53%
copy from third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change.html
copy to third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change-expected.html
index ff865ac56ca7747d0dded2e50fe0ca8f6b27ff95..da97c353512bd05a0d8c6b8946165da33b60a4a6 100644
--- a/third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change.html
+++ b/third_party/WebKit/LayoutTests/fast/repaint/multiple-backgrounds-style-change-expected.html
@@ -8,24 +8,8 @@
         background-size: 100px 100px;
         background-position: 0 0, 100px 100px;
         background-image: url('../images/resources/green-256x256.jpg'), url('../images/resources/dice.png');
-    }
-
-    .composited {
-        transform: translate3d(0, 0, 0);
-    }
-
-    .composited.changed {
         transform: translate3d(50px, 50px, 0);
     }
 </style>
-<script src="resources/text-based-repaint.js"></script>
-<script>
-    function repaintTest()
-    {
-        document.getElementById('test').classList.add('changed');
-    }
-
-    onload = runRepaintTest;
-</script>
-<div id="test" class="composited box">
-</div>
+<div id="test" class="box">
+</div>