Add support for passing an arbitrary parameter to an IPC message handler. The motivation is for Web…

ppapi/proxy/resource_message_test_sink.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/proxy/resource_message_test_sink.h"
 
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_message_params.h"
 #include "ppapi/proxy/serialized_handle.h"
 
 namespace ppapi {
 namespace proxy {
 
 namespace {
 
 // Backend for GetAllResource[Calls|Replies]Matching.
 template<class WrapperMessage, class Params>
 std::vector<std::pair<Params, IPC::Message> >
 GetAllResourceMessagesMatching(const ResourceMessageTestSink& sink,
                                uint32 id) {
   std::vector<std::pair<Params, IPC::Message> > result;
   for (size_t i = 0; i < sink.message_count(); i++) {
     const IPC::Message* msg = sink.GetMessageAt(i);
     if (msg->type() == WrapperMessage::ID) {
-      Params cur_params;
-      IPC::Message cur_msg;
-      WrapperMessage::Read(msg, &cur_params, &cur_msg);
+      typename WrapperMessage::Param params;
+      WrapperMessage::Read(msg, &params);
+      Params cur_params = params.a;
+      IPC::Message cur_msg = params.b;
       if (cur_msg.type() == id) {
         result.push_back(std::make_pair(cur_params, cur_msg));
       }
     }
   }
   return result;
 }
 
 }  // namespace
 
@@ skipping 105 matching lines @@
       wrapper_reply_msg, reply_params, reply_msg_);
   test_sink_->SetSyncReplyMessage(wrapper_reply_msg);
 
   // Stash a copy of the message for inspection later.
   last_handled_msg_ = call_msg;
   return true;
 }
 
 }  // namespace proxy
 }  // namespace ppapi