Make message listener API backwards compatible.

test/cctest/test-api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2670 matching lines @@
   CHECK(try_catch.Exception()->ToObject()->
             Get(v8_str("a"))->Equals(v8_str("b")));
 }
 
 
 bool message_received;
 
 
 static void check_message_0(v8::Handle<v8::Message> message,
                             v8::Handle<Value> data) {
+  CHECK_EQ(5.76, data->NumberValue());
   CHECK_EQ(6.75, message->GetScriptResourceName()->NumberValue());
   CHECK_EQ(7.56, message->GetScriptData()->NumberValue());
   message_received = true;
 }
 
 
 THREADED_TEST(MessageHandler0) {
   message_received = false;
   v8::HandleScope scope;
   CHECK(!message_received);
-  v8::V8::AddMessageListener(check_message_0);
+  v8::V8::AddMessageListener(check_message_0, v8_num(5.76));
   LocalContext context;
   v8::ScriptOrigin origin =
       v8::ScriptOrigin(v8_str("6.75"));
   v8::Handle<v8::Script> script = Script::Compile(v8_str("throw 'error'"),
                                                   &origin);
   script->SetData(v8_str("7.56"));
   script->Run();
   CHECK(message_received);
   // clear out the message listener
   v8::V8::RemoveMessageListeners(check_message_0);
@@ skipping 15503 matching lines @@
   i::Semaphore* sem_;
   volatile int sem_value_;
 };
 
 
 THREADED_TEST(SemaphoreInterruption) {
   ThreadInterruptTest().RunTest();
 }
 
 #endif  // WIN32