CSS Animations: Remove unnecessary webkit prefixes from layout tests

third_party/WebKit/LayoutTests/animations/multiple-keyframes.html

Index: third_party/WebKit/LayoutTests/animations/multiple-keyframes.html
diff --git a/third_party/WebKit/LayoutTests/animations/multiple-keyframes.html b/third_party/WebKit/LayoutTests/animations/multiple-keyframes.html
index a0f6add1a3c3762b81d7dc672b0e7bb91dc8477f..4120ab5aef888ade0fb7eb794614b20931db0285 100644
--- a/third_party/WebKit/LayoutTests/animations/multiple-keyframes.html
+++ b/third_party/WebKit/LayoutTests/animations/multiple-keyframes.html
@@ -13,11 +13,11 @@
       height: 100px;
       width: 100px;
       background-color: blue;
-      -webkit-animation-duration: 2s;
-      -webkit-animation-timing-function: linear;
-      -webkit-animation-name: anim;
+      animation-duration: 2s;
+      animation-timing-function: linear;
+      animation-name: anim;
     }
-    @-webkit-keyframes anim {
+    @keyframes anim {
         from { left: 10px; }
         40% { left: 30px; }
         60% { left: 10px; }