Use check item for side tab menu.

chrome/browser/browser.h

 // Copyright (c) 2010 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_BROWSER_H_
 #define CHROME_BROWSER_BROWSER_H_
 
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 514 matching lines @@
   void OpenThemeGalleryTabAndActivate();
   void OpenAutoFillHelpTabAndActivate();
   void OpenPrivacyDashboardTabAndActivate();
 #if defined(OS_CHROMEOS)
   void OpenSystemOptionsDialog();
   void OpenInternetOptionsDialog();
 #endif
 
   virtual void UpdateDownloadShelfVisibility(bool visible);
 
+  // Overridden from TabStripModelDelegate:
+  virtual bool UseVerticalTabs() const;
+
   /////////////////////////////////////////////////////////////////////////////
 
   // Sets the value of homepage related prefs to new values. Since we do not
   // want to change these values for existing users, we can not change the
   // default values under RegisterUserPrefs. Also if user already has an
   // existing profile we do not want to override those preferences so we only
   // set new values if they have not been set already. This method gets called
   // during First Run.
   static void SetNewHomePagePrefs(PrefService* prefs);
 
@@ skipping 95 matching lines @@
                                                SiteInstance* instance) const;
   virtual bool CanDuplicateContentsAt(int index);
   virtual void DuplicateContentsAt(int index);
   virtual void CloseFrameAfterDragSession();
   virtual void CreateHistoricalTab(TabContents* contents);
   virtual bool RunUnloadListenerBeforeClosing(TabContents* contents);
   virtual bool CanCloseContentsAt(int index);
   virtual bool CanBookmarkAllTabs() const;
   virtual void BookmarkAllTabs();
   virtual bool CanCloseTab() const;
-  virtual bool UseVerticalTabs() const;
   virtual void ToggleUseVerticalTabs();
   virtual bool CanRestoreTab();
   virtual void RestoreTab();
   virtual void SetToolbarVisibility(bool visible);
 
   // Overridden from TabStripModelObserver:
   virtual void TabInsertedAt(TabContents* contents,
                              int index,
                              bool foreground);
   virtual void TabClosingAt(TabContents* contents, int index);
@@ skipping 400 matching lines @@
   mutable BooleanPrefMember use_vertical_tabs_;
 
   // The profile's tab restore service. The service is owned by the profile,
   // and we install ourselves as an observer.
   TabRestoreService* tab_restore_service_;
 
   DISALLOW_COPY_AND_ASSIGN(Browser);
 };
 
 #endif  // CHROME_BROWSER_BROWSER_H_