CSS Animations: Reduce usage of setTimeout in Layout tests

third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html

Index: third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html
diff --git a/third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html b/third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html
index d799d9226adccc256cf2c3a5f00886d37c7f355f..649ce5a88d366d3df6a649daffe1dbe9064bf787 100644
--- a/third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html
+++ b/third_party/WebKit/LayoutTests/animations/animation-events-prefixed-01.html
@@ -47,10 +47,10 @@
       endEventReceived = true;
       document.getElementById('box').className = '';
       // Launch again the animation to catch the animation iteration events this time.
-      setTimeout(function () {
+      requestAnimationFrame(function () {
         document.getElementById('box').style.webkitAnimationIterationCount = "infinite";
         document.getElementById('box').className = 'animate';
-      }, 200);
+      });
     }, false);
 
     onload = function()