Don't send PP_Vars/V8 values with cycles across PostMessage

ppapi/c/ppp_messaging.h

Index: ppapi/c/ppp_messaging.h
diff --git a/ppapi/c/ppp_messaging.h b/ppapi/c/ppp_messaging.h
index b2e1f3cea22ec60b9d8bd5cc85e5d06de47811b1..28d40d6e4b8ea30f8d124b28b7278a536d75b071 100644
--- a/ppapi/c/ppp_messaging.h
+++ b/ppapi/c/ppp_messaging.h
@@ -3,7 +3,7 @@
  * found in the LICENSE file.
  */
 
-/* From ppp_messaging.idl modified Tue May 21 09:01:17 2013. */
+/* From ppp_messaging.idl modified Wed Jun  5 10:32:43 2013. */
 
 #ifndef PPAPI_C_PPP_MESSAGING_H_
 #define PPAPI_C_PPP_MESSAGING_H_
@@ -52,10 +52,9 @@ struct PPP_Messaging_1_0 {
    *
    * When converting JavaScript arrays, any object properties whose name
    * is not an array index are ignored. When passing arrays and objects, the
-   * entire reference graph will be converted and transferred, including
-   * reference cycles if they exist. Since <code>PP_Var</code>s are ref-counted,
-   * the author of the plugin must take care if they expect to receive vars with
-   * cycles. Cycles must be manually broken to correctly release the vars.
+   * entire reference graph will be converted and transferred. If the reference
+   * graph has cycles, the message will not be sent and an error will be logged
+   * to the console.
    *
    * The following JavaScript code invokes <code>HandleMessage</code>, passing
    * the module instance on which it was invoked, with <code>message</code>