GTK: More transitions to thunk definition macros.

chrome/browser/gtk/external_protocol_dialog_gtk.h

 // Copyright (c) 2009 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.
 
 #ifndef CHROME_BROWSER_GTK_EXTERNAL_PROTOCOL_DIALOG_GTK_H_
 #define CHROME_BROWSER_GTK_EXTERNAL_PROTOCOL_DIALOG_GTK_H_
 
+#include "app/gtk_signal.h"
 #include "base/time.h"
 #include "googleurl/src/gurl.h"
 
 class TabContents;
 
 typedef struct _GtkWidget GtkWidget;
 
 class ExternalProtocolDialogGtk {
  public:
   explicit ExternalProtocolDialogGtk(const GURL& url);
 
  private:
-  static void OnDialogResponseThunk(GtkWidget* widget,
-                                    int response,
-                                    ExternalProtocolDialogGtk* dialog) {
-    dialog->OnDialogResponse(response);
-  }
-  void OnDialogResponse(int response);
+  CHROMEGTK_CALLBACK_1(ExternalProtocolDialogGtk, void, OnDialogResponse, int);
 
   GtkWidget* dialog_;
   GtkWidget* checkbox_;
   GURL url_;
   base::Time creation_time_;
 };
 
 #endif  // CHROME_BROWSER_GTK_EXTERNAL_PROTOCOL_DIALOG_GTK_H_