Refactor 4 PPB_Flash functions to the new PPAPI resource model.

ppapi/host/resource_message_handler.cc

 // 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.
 
 #include "ppapi/host/resource_message_handler.h"
 
 #include "base/logging.h"
 #include "ipc/ipc_message.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/host/host_message_context.h"
 
 namespace ppapi {
 namespace host {
 
 ResourceMessageHandler::ResourceMessageHandler() {
 }
 
 ResourceMessageHandler::~ResourceMessageHandler() {
 }
 
 void ResourceMessageHandler::RunMessageHandlerAndReply(
     const IPC::Message& msg,
     HostMessageContext* context) {
   ReplyMessageContext reply_context = context->MakeReplyMessageContext();
+  // CAUTION: Handling the message may cause the destruction of this object.
+  // The message handler should ensure that if there is a chance that the
+  // object will be destroyed, PP_OK_COMPLETIONPENDING is returned as the
+  // result of the message handler. Otherwise the code below will attempt to
+  // send a reply message on a destroyed object.
   reply_context.params.set_result(OnResourceMessageReceived(msg, context));
 
   // Sanity check the resource handler. Note if the result was
   // "completion pending" the resource host may have already sent the reply.
   if (reply_context.params.result() == PP_OK_COMPLETIONPENDING) {
     // Message handler should have only returned a pending result if a
     // response will be sent to the plugin.
     DCHECK(context->params.has_callback());
 
     // Message handler should not have written a message to be returned if
@@ skipping 16 matching lines @@
 }
 
 int32_t ResourceMessageHandler::OnResourceMessageReceived(
     const IPC::Message& msg,
     HostMessageContext* context) {
   return PP_ERROR_NOTSUPPORTED;
 }
 
 }  // namespace host
 }  // namespace ppapi