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

ppapi/c/ppb_messaging.h

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-/* From ppb_messaging.idl modified Mon May 20 15:31:07 2013. */
+/* From ppb_messaging.idl modified Mon Jun  3 12:26:57 2013. */
 
 #ifndef PPAPI_C_PPB_MESSAGING_H_
 #define PPAPI_C_PPB_MESSAGING_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
 
@@ skipping 26 matching lines @@
    * @param[in] instance A <code>PP_Instance</code> identifying one instance
    * of a module.
    * @param[in] message A <code>PP_Var</code> containing the data to be sent to
    * JavaScript.
    * <code>message</code> can be any <code>PP_Var</code> type except
    * <code>PP_VARTYPE_OBJECT</code>. Array/Dictionary types are supported from
    * Chrome M29 onward. All var types are copied when passing them to
    * JavaScript.
    *
    * When passing array or dictionary <code>PP_Var</code>s, the entire reference
-   * graph will be converted and transferred, including reference cycles if they
-   * exist.
+   * graph will be converted and transferred. If the reference graph has cycles,
+   * an undefined var will be sent instead and an error will be logged to the
+   * console.
    *
    * Listeners for message events in JavaScript code will receive an object
    * conforming to the HTML 5 <code>MessageEvent</code> interface.
    * Specifically, the value of message will be contained as a property called
    *  data in the received <code>MessageEvent</code>.
    *
    * This messaging system is similar to the system used for listening for
    * messages from Web Workers. Refer to
    * <code>http://www.whatwg.org/specs/web-workers/current-work/</code> for
    * further information.
@@ skipping 33 matching lines @@
   void (*PostMessage)(PP_Instance instance, struct PP_Var message);
 };
 
 typedef struct PPB_Messaging_1_0 PPB_Messaging;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPB_MESSAGING_H_ */