Unprefix usage of -webkit-transform in tests

LayoutTests/fast/repaint/transform-absolute-child.html

Index: LayoutTests/fast/repaint/transform-absolute-child.html
diff --git a/LayoutTests/fast/repaint/transform-absolute-child.html b/LayoutTests/fast/repaint/transform-absolute-child.html
index ba0f9c8bf73d538c9689150df144b3589f7b40ad..f11419a51dced5f0dbd3b62220f1e64f349b9726 100644
--- a/LayoutTests/fast/repaint/transform-absolute-child.html
+++ b/LayoutTests/fast/repaint/transform-absolute-child.html
@@ -11,10 +11,10 @@
         width: 200px;
         height: 200px;
         border: 2px solid black;
-        -webkit-transform: rotate(0deg);
+        transform: rotate(0deg);
      }
      #box.rotated {
-        -webkit-transform: rotate(40deg);
+        transform: rotate(40deg);
      }
      #child {
         position: absolute;