Changes instant so that the newly created tab has a new id. Doing

chrome/browser/gtk/tabs/tab_strip_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_TABS_TAB_STRIP_GTK_H_
 #define CHROME_BROWSER_GTK_TABS_TAB_STRIP_GTK_H_
 #pragma once
 
 #include <gtk/gtk.h>
 #include <vector>
@@ skipping 97 matching lines @@
   virtual void TabDetachedAt(TabContentsWrapper* contents, int index);
   virtual void TabSelectedAt(TabContentsWrapper* old_contents,
                              TabContentsWrapper* contents,
                              int index,
                              bool user_gesture);
   virtual void TabMoved(TabContentsWrapper* contents,
                         int from_index,
                         int to_index);
   virtual void TabChangedAt(TabContentsWrapper* contents, int index,
                             TabChangeType change_type);
-  virtual void TabReplacedAt(TabContentsWrapper* old_contents,
+  virtual void TabReplacedAt(TabStripModel* tab_strip_model,
+                             TabContentsWrapper* old_contents,
                              TabContentsWrapper* new_contents,
                              int index);
   virtual void TabMiniStateChanged(TabContentsWrapper* contents, int index);
   virtual void TabBlockedStateChanged(TabContentsWrapper* contents,
                                       int index);
 
   // TabGtk::TabDelegate implementation:
   virtual bool IsTabSelected(const TabGtk* tab) const;
   virtual bool IsTabPinned(const TabGtk* tab) const;
   virtual bool IsTabDetached(const TabGtk* tab) const;
@@ skipping 327 matching lines @@
   // ResizeLayoutTabsNow method.
   ScopedRunnableMethodFactory<TabStripGtk> resize_layout_factory_;
 
   // True if the tabstrip has already been added as a MessageLoop observer.
   bool added_as_message_loop_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(TabStripGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_TABS_TAB_STRIP_GTK_H_