Make sure manifest specified shortcut for Extension Command can not override the built-in shortcuts.

chrome/browser/ui/views/frame/browser_view.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_VIEWS_FRAME_BROWSER_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_VIEW_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 170 matching lines @@
 
   // Handle the specified |accelerator| being pressed.
   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
 
   // Provides the containing frame with the accelerator for the specified
   // command id. This can be used to provide menu item shortcut hints etc.
   // Returns true if an accelerator was found for the specified |cmd_id|, false
   // otherwise.
   bool GetAccelerator(int cmd_id, ui::Accelerator* accelerator);
 
+  // Returns true if the specificed |accelerator| is registered with this view.
+  bool IsAcceleratorRegistered(const ui::Accelerator& accelerator);
+
   // Returns the active WebContents. Used by our NonClientView's
   // TabIconView::TabContentsProvider implementations.
   // TODO(beng): exposing this here is a bit bogus, since it's only used to
   // determine loading state. It'd be nicer if we could change this to be
   // bool IsSelectedTabLoading() const; or something like that. We could even
   // move it to a WindowDelegate subclass.
   content::WebContents* GetActiveWebContents() const;
 
   // Retrieves the icon to use in the frame to indicate an OTR window.
   gfx::ImageSkia GetOTRAvatarIcon() const;
@@ skipping 547 matching lines @@
   gfx::ScopedSysColorChangeListener color_change_listener_;
 
   scoped_ptr<InstantOverlayControllerViews> overlay_controller_;
 
   mutable base::WeakPtrFactory<BrowserView> activate_modal_dialog_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_VIEW_H_