CSS Animations: Remove unnecessary webkit prefixes from layout tests

third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html

Index: third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html
diff --git a/third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html b/third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html
index cd8f3533eb92f59b3c25a4c292802bae2e2a7ffa..480b5e6ac77f1bcbea1d033db1b8edf08321edaa 100644
--- a/third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html
+++ b/third_party/WebKit/LayoutTests/animations/animation-direction-alternate-reverse.html
@@ -16,15 +16,15 @@
       height: 100px;
       width: 100px;
       background-color: blue;
-      -webkit-animation-name: move;
-      -webkit-animation-duration: 2s;
-      -webkit-animation-direction: alternate-reverse;
-      -webkit-animation-iteration-count: 2;
-      -webkit-animation-timing-function: linear;
-      -webkit-animation-fill-mode: forwards;
+      animation-name: move;
+      animation-duration: 2s;
+      animation-direction: alternate-reverse;
+      animation-iteration-count: 2;
+      animation-timing-function: linear;
+      animation-fill-mode: forwards;
     }
 
-    @-webkit-keyframes move {
+    @keyframes move {
       0%   {
         left: 0;
       }