Get rid of [Callback] extended attribute for parameters in IDL files

Source/core/page/DOMWindow.idl

Index: Source/core/page/DOMWindow.idl
diff --git a/Source/core/page/DOMWindow.idl b/Source/core/page/DOMWindow.idl
index 006b0c8a9709a17119cd430963a7c2dc300d1e84..d70eeba78adbdc3400aab7c50ec2912904520ce1 100644
--- a/Source/core/page/DOMWindow.idl
+++ b/Source/core/page/DOMWindow.idl
@@ -174,9 +174,9 @@
     [Custom] long setInterval(any handler, [Default=Undefined] optional long timeout);
     void clearInterval([Default=Undefined] optional long handle);
 
-    [MeasureAs=UnprefixedRequestAnimationFrame] long requestAnimationFrame([Callback] RequestAnimationFrameCallback callback);
+    [MeasureAs=UnprefixedRequestAnimationFrame] long requestAnimationFrame(RequestAnimationFrameCallback callback);
     void cancelAnimationFrame(long id);
-    [MeasureAs=PrefixedRequestAnimationFrame] long webkitRequestAnimationFrame([Callback] RequestAnimationFrameCallback callback);
+    [MeasureAs=PrefixedRequestAnimationFrame] long webkitRequestAnimationFrame(RequestAnimationFrameCallback callback);
     [ImplementedAs=cancelAnimationFrame] void webkitCancelAnimationFrame(long id);
     [ImplementedAs=cancelAnimationFrame] void webkitCancelRequestAnimationFrame(long id); // This is a deprecated alias for webkitCancelAnimationFrame(). Remove this when removing vendor prefix.