Fix the segfault on Linux when closing a tab that is in tab fullscreen mode.

chrome/browser/ui/gtk/fullscreen_exit_bubble_gtk.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_GTK_FULLSCREEN_EXIT_BUBBLE_GTK_H_
 #define CHROME_BROWSER_UI_GTK_FULLSCREEN_EXIT_BUBBLE_GTK_H_
 #pragma once
 
 #include "chrome/browser/ui/fullscreen_exit_bubble.h"
 #include "chrome/browser/ui/fullscreen_exit_bubble_type.h"
@@ skipping 38 matching lines @@
   }
 
   CHROMEGTK_CALLBACK_1(FullscreenExitBubbleGtk, void, OnSetFloatingPosition,
                        GtkAllocation*);
   CHROMEGTK_CALLBACK_0(FullscreenExitBubbleGtk, void, OnLinkClicked);
   CHROMEGTK_CALLBACK_0(FullscreenExitBubbleGtk, void, OnAllowClicked);
   CHROMEGTK_CALLBACK_0(FullscreenExitBubbleGtk, void, OnDenyClicked);
 
   // A pointer to the floating container that is our parent.
   GtkFloatingContainer* container_;
-  GtkWidget* render_widget_host_view_widget_;
 
   // The widget that contains the UI.
   ui::OwnedWidgetGtk ui_container_;
   GtkWidget* instruction_label_;
   GtkWidget* hbox_;
   GtkWidget* message_label_;
   GtkWidget* button_link_hbox_;
   GtkWidget* link_;
   GtkWidget* allow_button_;
   GtkWidget* deny_button_;
 
   // The widget that animates the slide-out of fullscreen exit bubble.
   scoped_ptr<SlideAnimatorGtk> slide_widget_;
 
   // The timer that does the initial hiding of the exit bubble.
   base::OneShotTimer<FullscreenExitBubbleGtk> initial_delay_;
 
   ui::GtkSignalRegistrar signals_;
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_FULLSCREEN_EXIT_BUBBLE_GTK_H_