GTK: Remove use of deprecated gtk_dialog_set_has_separator

chrome/browser/ui/gtk/extensions/extension_install_dialog_gtk.cc

 // Copyright (c) 2011 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.
 
 #include <gtk/gtk.h>
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_install_dialog.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 73 matching lines @@
       NULL);
   GtkWidget* close_button = gtk_dialog_add_button(
       GTK_DIALOG(dialog_),
       prompt.HasAbortButtonLabel() ?
           UTF16ToUTF8(prompt.GetAbortButtonLabel()).c_str() : GTK_STOCK_CANCEL,
       GTK_RESPONSE_CLOSE);
   gtk_dialog_add_button(
       GTK_DIALOG(dialog_),
       UTF16ToUTF8(prompt.GetAcceptButtonLabel()).c_str(),
       GTK_RESPONSE_ACCEPT);
+#if !GTK_CHECK_VERSION(2, 22, 0)
   gtk_dialog_set_has_separator(GTK_DIALOG(dialog_), FALSE);
+#endif
 
   GtkWidget* content_area = gtk_dialog_get_content_area(GTK_DIALOG(dialog_));
   gtk_box_set_spacing(GTK_BOX(content_area), ui::kContentAreaSpacing);
 
   // Divide the dialog vertically (item data and icon on the top, permissions
   // on the bottom).
   GtkWidget* content_vbox = gtk_vbox_new(FALSE, ui::kControlSpacing);
   gtk_box_pack_start(GTK_BOX(content_area), content_vbox, TRUE, TRUE, 0);
 
   // Create a two column layout for the top (item data on the left, icon on
@@ skipping 149 matching lines @@
     delegate->InstallUIAbort(false);
     return;
   }
 
   new ExtensionInstallDialog(browser_window->window(),
                              delegate,
                              extension,
                              icon,
                              prompt);
 }