Add a context menu to the tab strip. It appears when you click in the

chrome/browser/tabs/tab_strip_model.h

 // Copyright (c) 2006-2008 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_TABS_TAB_STRIP_MODEL_H_
 #define CHROME_BROWSER_TABS_TAB_STRIP_MODEL_H_
 
 #include <vector>
 
 #include "base/observer_list.h"
@@ skipping 402 matching lines @@
   enum ContextMenuCommand {
     CommandFirst = 0,
     CommandNewTab,
     CommandReload,
     CommandDuplicate,
     CommandCloseTab,
     CommandCloseOtherTabs,
     CommandCloseTabsToRight,
     CommandCloseTabsOpenedBy,
     CommandRestoreTab,
+    CommandTaskManager,
     CommandLast
   };
 
   // Returns true if the specified command is enabled.
   bool IsContextMenuCommandEnabled(int context_index,
                                    ContextMenuCommand command_id) const;
 
   // Performs the action associated with the specified command for the given
   // TabStripModel index |context_index|.
   void ExecuteContextMenuCommand(int context_index,
@@ skipping 139 matching lines @@
   typedef ObserverList<TabStripModelObserver> TabStripModelObservers;
   TabStripModelObservers observers_;
 
   // A scoped container for notification registries.
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(TabStripModel);
 };
 
 #endif  // CHROME_BROWSER_TABS_TAB_STRIP_MODEL_H_