The Mac wrench menu zoom controls honor the global enabled state of the zoom commands.

chrome/browser/wrench_menu_model.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_WRENCH_MENU_MODEL_H_
 #define CHROME_BROWSER_WRENCH_MENU_MODEL_H_
 #pragma once
 
 #include <set>
 #include <vector>
@@ skipping 76 matching lines @@
   // Overridden from menus::SimpleMenuModel:
   virtual bool IsLabelDynamicAt(int index) const;
   virtual string16 GetLabelAt(int index) const;
   virtual bool HasIcons() const { return true; }
   virtual bool GetIconAt(int index, SkBitmap* icon) const;
 
   // Overridden from menus::ButtonMenuItemModel::Delegate:
   virtual bool IsLabelForCommandIdDynamic(int command_id) const;
   virtual string16 GetLabelForCommandId(int command_id) const;
   virtual void ExecuteCommand(int command_id);
+  virtual bool IsCommandIdEnabled(int command_id) const;
 
   // Overridden from TabStripModelObserver:
   virtual void TabSelectedAt(TabContents* old_contents,
                              TabContents* new_contents,
                              int index,
                              bool user_gesture);
   virtual void TabReplacedAt(TabContents* old_contents,
                              TabContents* new_contents, int index);
   virtual void TabStripModelDeleted();
 
@@ skipping 39 matching lines @@
 
   Browser* browser_;  // weak
   TabStripModel* tabstrip_model_; // weak
 
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(WrenchMenuModel);
 };
 
 #endif  // CHROME_BROWSER_WRENCH_MENU_MODEL_H_