DISALLOW_COPY_AND_ASSIGN the TabStripModelObserver.

chrome/browser/ui/tabs/tab_strip_model_observer.h

 // Copyright (c) 2012 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_TABS_TAB_STRIP_MODEL_OBSERVER_H_
 #define CHROME_BROWSER_UI_TABS_TAB_STRIP_MODEL_OBSERVER_H_
 
+#include "base/macros.h"
+
 class TabStripModel;
 
 namespace content {
 class WebContents;
 }
 
 namespace ui {
 class ListSelectionModel;
 }
 
@@ skipping 127 matching lines @@
   // Sent any time an attempt is made to close all the tabs. This is not
   // necessarily the result of CloseAllTabs(). For example, if the user closes
   // the last tab WillCloseAllTabs() is sent. If the close does not succeed
   // during the current event (say unload handlers block it) then
   // CloseAllTabsCanceled() is sent. Also note that if the last tab is detached
   // (DetachWebContentsAt()) then this is not sent.
   virtual void WillCloseAllTabs();
   virtual void CloseAllTabsCanceled();
 
  protected:
+  TabStripModelObserver();
   virtual ~TabStripModelObserver() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TabStripModelObserver);
 };
 
 #endif  // CHROME_BROWSER_UI_TABS_TAB_STRIP_MODEL_OBSERVER_H_