Reland 95309. Add a template to handle properly issuing completion callbacks.

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_.NewOptionalCallback(
-      &PPB_Flash_Menu_Proxy::SendShowACKToPlugin, request);
 
-  EnterHostFromHostResource<PPB_Flash_Menu_API> enter(menu);
-  int32_t result = PP_ERROR_BADRESOURCE;
+  EnterHostFromHostResourceForceCallback<PPB_Flash_Menu_API> enter(
+      menu, callback_factory_, &PPB_Flash_Menu_Proxy::SendShowACKToPlugin,
+      request);
   if (enter.succeeded()) {
-    result = enter.object()->Show(&location,
-                                  &request->selected_id,
-                                  callback.pp_completion_callback());
-  }
-  if (result != PP_OK_COMPLETIONPENDING) {
-    // There was some error, so we won't get a callback. We need to now issue
-    // the ACK to the plugin so that it hears about the error. This will also
-    // clean up the data associated with the callback.
-    callback.Run(result);
+    enter.SetResult(enter.object()->Show(&location, &request->selected_id,
+                                         enter.callback()));
   }
 }
 
 void PPB_Flash_Menu_Proxy::OnMsgShowACK(const HostResource& menu,
                                         int32_t selected_id,
                                         int32_t result) {
   EnterPluginFromHostResource<PPB_Flash_Menu_API> enter(menu);
   if (enter.failed())
     return;
   static_cast<FlashMenu*>(enter.object())->ShowACK(selected_id, result);
 }
 
 void PPB_Flash_Menu_Proxy::SendShowACKToPlugin(
     int32_t result,
     ShowRequest* request) {
   dispatcher()->Send(new PpapiMsg_PPBFlashMenu_ShowACK(
       INTERFACE_ID_PPB_FLASH_MENU,
       request->menu,
       request->selected_id,
       result));
   delete request;
 }
 
 }  // namespace proxy
 }  // namespace pp