Prevent Pepper plugin reentrncy for synchronous messages.

ppapi/proxy/ppb_var_deprecated_proxy.h

 // Copyright (c) 2010 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.
 
 #ifndef PPAPI_PPB_VAR_PROXY_H_
 #define PPAPI_PPB_VAR_PROXY_H_
 
 #include <vector>
 
 #include "ppapi/c/pp_instance.h"
@@ skipping 69 matching lines @@
                       SerializedVarOutParam exception,
                       SerializedVarReturnValue result);
   void OnMsgIsInstanceOfDeprecated(pp::proxy::SerializedVarReceiveInput var,
                                    int64 ppp_class,
                                    int64* ppp_class_data,
                                    PP_Bool* result);
   void OnMsgCreateObjectDeprecated(PP_Instance instance,
                                    int64 ppp_class,
                                    int64 ppp_class_data,
                                    SerializedVarReturnValue result);
+
+  // Call in the host for messages that can be reentered.
+  void SetAllowPluginReentrancy();
 };
 
 }  // namespace proxy
 }  // namespace pp
 
 #endif  // PPAPI_PPB_VAR_PROXY_H_