In ~BrowserToolbarGtk, remove notifications we added in the ctor....

chrome/browser/gtk/browser_toolbar_gtk.cc

 // 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.
 
 #include "chrome/browser/gtk/browser_toolbar_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 #include <X11/XF86keysym.h>
 
 #include "app/gfx/gtk_util.h"
@@ skipping 75 matching lines @@
   browser_->command_updater()->AddCommandObserver(IDC_RELOAD, this);
   browser_->command_updater()->AddCommandObserver(IDC_HOME, this);
   browser_->command_updater()->AddCommandObserver(IDC_BOOKMARK_PAGE, this);
 
   registrar_.Add(this,
                  NotificationType::BROWSER_THEME_CHANGED,
                  NotificationService::AllSources());
 }
 
 BrowserToolbarGtk::~BrowserToolbarGtk() {
+  browser_->command_updater()->RemoveCommandObserver(IDC_BACK, this);
+  browser_->command_updater()->RemoveCommandObserver(IDC_FORWARD, this);
+  browser_->command_updater()->RemoveCommandObserver(IDC_RELOAD, this);
+  browser_->command_updater()->RemoveCommandObserver(IDC_HOME, this);
+  browser_->command_updater()->RemoveCommandObserver(IDC_BOOKMARK_PAGE, this);
+
   offscreen_entry_.Destroy();
 
   // When we created our MenuGtk objects, we pass them a pointer to our accel
   // group. Make sure to tear them down before |accel_group_|.
   page_menu_.reset();
   app_menu_.reset();
   page_menu_button_.Destroy();
   app_menu_button_.Destroy();
   g_object_unref(accel_group_);
 }
@@ skipping 584 matching lines @@
   menu->PopupAsFromKeyEvent(button);
   menu_bar_helper_.MenuStartedShowing(button, menu->widget());
 }
 
 void BrowserToolbarGtk::PopupForButtonNextTo(GtkWidget* button,
                                              GtkMenuDirectionType dir) {
   GtkWidget* other_button = button == page_menu_button_.get() ?
       app_menu_button_.get() : page_menu_button_.get();
   PopupForButton(other_button);
 }