Unprefix usage of -webkit-transform in tests

LayoutTests/media/video-transformed.html

Index: LayoutTests/media/video-transformed.html
diff --git a/LayoutTests/media/video-transformed.html b/LayoutTests/media/video-transformed.html
index 3c1a72b7d79dd3cf26cde44c6353c9bdd26f84a0..1e64bf9b8d24aae3704c38627564ff4ad1b6c6f3 100644
--- a/LayoutTests/media/video-transformed.html
+++ b/LayoutTests/media/video-transformed.html
@@ -5,9 +5,9 @@
 video { width:200px; border: 3px solid red; }
 </style>
 <p>Test painting of transformed video </p>
-&nbsp;<video style="-webkit-transform:rotate(20deg)"></video><br>
-&nbsp;<video style="-webkit-transform:scale(0.5)"></video><br>
-&nbsp;<video style="-webkit-transform:skew(20deg)"></video><br>
+&nbsp;<video style="transform:rotate(20deg)"></video><br>
+&nbsp;<video style="transform:scale(0.5)"></video><br>
+&nbsp;<video style="transform:skew(20deg)"></video><br>
 <script>
 init();
 setSrcByTagName('video', findMediaFile('video', 'content/test'));