Fix unload debugger

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 3366 matching lines @@
     i::Debugger::SetMessageHandler(MessageHandlerWrapper);
   } else {
     i::Debugger::SetMessageHandler(NULL);
   }
 }
 
 
 void Debug::SetMessageHandler2(v8::Debug::MessageHandler2 handler) {
   EnsureInitialized("v8::Debug::SetMessageHandler");
   ENTER_V8;
+  HandleScope scope;
   i::Debugger::SetMessageHandler(handler);
 }
 
 
 void Debug::SendCommand(const uint16_t* command, int length,
                         ClientData* client_data) {
   if (!i::V8::IsRunning()) 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