Refactor of various layout tests to use RAF

LayoutTests/resources/js-test.js

Index: LayoutTests/resources/js-test.js
diff --git a/LayoutTests/resources/js-test.js b/LayoutTests/resources/js-test.js
index 45fa85dcfd7865479fd9aca4638b80cd37038399..216e23005d293e88e2793b15885f1755f4b5948e 100644
--- a/LayoutTests/resources/js-test.js
+++ b/LayoutTests/resources/js-test.js
@@ -691,7 +691,7 @@ function shouldHaveHadError(message)
 // function.
 function asyncGC(callback) {
     GCController.collectAll();
-    setTimeout(callback, 0);
+    requestAnimationFrame(callback);

[eseidel, 2014/10/14 16:15:58]

I might leave a comment to explain why RAF works beter.  Fore xample it always
goes through the event loop?

 }
 
 function gc() {
@@ -715,7 +715,7 @@ function asyncMinorGC(callback) {
         GCController.minorCollect();
     else
         testFailed("Minor GC is available only when you enable the --expose-gc option in V8.");
-    setTimeout(callback, 0);
+    requestAnimationFrame(callback);
 }
 
 function isSuccessfullyParsed()