PPAPI: Force async callback invocation option.

ppapi/proxy/ppb_flash_menu_proxy.cc

 // Copyright (c) 2011 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.
 
 #include "ppapi/proxy/ppb_flash_menu_proxy.h"
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/private/ppb_flash_menu.h"
 #include "ppapi/proxy/enter_proxy.h"
 #include "ppapi/proxy/ppapi_messages.h"
@@ skipping 144 matching lines @@
 
 struct PPB_Flash_Menu_Proxy::ShowRequest {
   HostResource menu;
   int32_t selected_id;
 };
 
 void PPB_Flash_Menu_Proxy::OnMsgShow(const HostResource& menu,
                                      const PP_Point& location) {
   ShowRequest* request = new ShowRequest;
   request->menu = menu;
-  CompletionCallback callback = callback_factory_.NewCallback(
+  CompletionCallback callback = callback_factory_.NewOptionalCallback(
       &PPB_Flash_Menu_Proxy::SendShowACKToPlugin, request);
 
   EnterHostFromHostResource<PPB_Flash_Menu_API> enter(menu);
   int32_t result = PP_ERROR_BADRESOURCE;
   if (enter.succeeded()) {
     result = enter.object()->Show(&location,
                                   &request->selected_id,
                                   callback.pp_completion_callback());
   }
   if (result != PP_OK_COMPLETIONPENDING) {
@@ skipping 19 matching lines @@
   dispatcher()->Send(new PpapiMsg_PPBFlashMenu_ShowACK(
       INTERFACE_ID_PPB_FLASH_MENU,
       request->menu,
       request->selected_id,
       result));
   delete request;
 }
 
 }  // namespace proxy
 }  // namespace pp