Create a transition API for the debug message handler

src/api.cc

 // Copyright 2009 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 3242 matching lines @@
   return true;
 }
 
 
 void Debug::DebugBreak() {
   if (!i::V8::HasBeenSetup()) return;
   i::StackGuard::DebugBreak();
 }
 
 
+static v8::Debug::MessageHandler message_handler = NULL;
+
+static void MessageHandlerWrapper(const v8::Debug::Message& message) {
+  if (message_handler) {
+    v8::String::Value json(message.GetJSON());
+    message_handler(*json, json.length(), message.GetClientData());
+  }
+}
+
+
 void Debug::SetMessageHandler(v8::Debug::MessageHandler handler,
                               bool message_handler_thread) {
   EnsureInitialized("v8::Debug::SetMessageHandler");
   ENTER_V8;
   // Message handler thread not supported any more. Parameter temporally left in
   // the API for client compatability reasons.
   CHECK(!message_handler_thread);
+
+  // TODO(sgjesse) support the old message handler API through a simple wrapper.
+  message_handler = handler;
+  if (message_handler != NULL) {
+    i::Debugger::SetMessageHandler(MessageHandlerWrapper);
+  } else {
+    i::Debugger::SetMessageHandler(NULL);
+  }
+}
+
+
+void Debug::SetMessageHandler2(v8::Debug::MessageHandler2 handler) {
+  EnsureInitialized("v8::Debug::SetMessageHandler");
+  ENTER_V8;
   i::Debugger::SetMessageHandler(handler);
 }
 
 
 void Debug::SendCommand(const uint16_t* command, int length,
                         ClientData* client_data) {
   if (!i::V8::HasBeenSetup()) return;
   i::Debugger::ProcessCommand(i::Vector<const uint16_t>(command, length),
                               client_data);
 }
@@ skipping 107 matching lines @@
       reinterpret_cast<HandleScopeImplementer*>(storage);
   List<void**>* blocks_of_archived_thread = thread_local->Blocks();
   v8::ImplementationUtilities::HandleScopeData* handle_data_of_archived_thread =
       &thread_local->handle_scope_data_;
   Iterate(v, blocks_of_archived_thread, handle_data_of_archived_thread);
 
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal