Flushing out requestAnimationFrame polyfill further.

lib/html/idl/dart/dart.idl

Index: lib/html/idl/dart/dart.idl
diff --git a/lib/html/idl/dart/dart.idl b/lib/html/idl/dart/dart.idl
index e7ccb98b1418d0a58225c7b4ade64200c2f7a4dc..d9b739d84d473375f131c6ccaacf5a688b072a7f 100644
--- a/lib/html/idl/dart/dart.idl
+++ b/lib/html/idl/dart/dart.idl
@@ -347,3 +347,11 @@ module websockets {
   };
 }
 
+module core {
+  [supplemental, Callback]
+  interface RequestAnimationFrameCallback {
+    // Webkit implements this as returning bool, but standard is void.
+    [Suppressed] boolean handleEvent(in DOMTimeStamp time);
+    void handleEvent(in DOMTimeStamp time);
+  };
+}