1. Create a port when a debugger object is created for an isolate, use this

bin/dbg_message.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_DBG_MESSAGE_H_
 #define BIN_DBG_MESSAGE_H_
 
 #include "bin/builtin.h"
 #include "bin/utils.h"
 
@@ skipping 158 matching lines @@
   static DbgMessageQueue* GetIsolateMessageQueue(Dart_Isolate isolate);
 
   // Generic handlers for breakpoints, exceptions and delayed breakpoint
   // resolution.
   static void BptResolvedHandler(intptr_t bp_id,
                                  Dart_Handle url,
                                  intptr_t line_number);
   static void BreakpointHandler(Dart_Breakpoint bpt, Dart_StackTrace trace);
   static void ExceptionThrownHandler(Dart_Handle exception,
                                      Dart_StackTrace stack_trace);
-  static void IsolateEventHandler(Dart_Isolate isolate,
+  static void IsolateEventHandler(Dart_IsolateId isolate_id,
                                   Dart_IsolateEvent kind);
 
  private:
   bool is_running_;  // True if isolate is running and not in the debugger loop.
   bool is_interrupted_;  // True if interrupt command is pending.
 
   DbgMessage* msglist_head_;  // Start of debugger messages list.
   DbgMessage* msglist_tail_;  // End of debugger messages list.
 
   // Text buffer that accumulates messages to be output.
   dart::TextBuffer queued_output_messages_;
 
   // The waits on this condition variable when it needs to process
   // debug messages.
   dart::Monitor msg_queue_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(DbgMessageQueue);
 };
 
 #endif  // BIN_DBG_MESSAGE_H_