Add power-user keyboard mode for ChromeOS with Search key acting as a typical Fn key.

ash/shell_delegate.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 ASH_SHELL_DELEGATE_H_
 #define ASH_SHELL_DELEGATE_H_
 
 #include <vector>
 
 #include "ash/ash_export.h"
@@ skipping 171 matching lines @@
 
   // Gets a saved value of the zoom scale of full screen magnifier. If a value
   // is not saved, return a negative value.
   virtual double GetSavedScreenMagnifierScale() = 0;
 
   // Creates a menu model of the context for the |root_window|.
   virtual ui::MenuModel* CreateContextMenu(aura::RootWindow* root_window) = 0;
 
   // Creates the stacking client. Shell takes ownership of the object.
   virtual aura::client::StackingClient* CreateStackingClient() = 0;
+
+  // True if the user's preferences have the Search key acting as a Function key
+  // modifier for accessing extended keyboard shortcuts.
+  virtual bool IsSearchKeyActingAsFunctionKey() const = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_DELEGATE_H_