Enable Virtual Screen Coordinates

ash/shell.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_H_
 #define ASH_SHELL_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 377 matching lines @@
   virtual void ShowCursor(bool visible) OVERRIDE;
 
   static Shell* instance_;
 
   // If set before the Shell is initialized, the mouse cursor will be hidden
   // when the screen is initially created.
   static bool initially_hide_cursor_;
 
   ScreenAsh* screen_;
 
-  // Active root window. Never become NULL.
+  // Active root window. Never becomes NULL during the session.
   aura::RootWindow* active_root_window_;
 
   // The CompoundEventFilter owned by aura::Env object.
   aura::shared::CompoundEventFilter* env_filter_;
 
   std::vector<WindowAndBoundsPair> to_restore_;
 
 #if !defined(OS_MACOSX)
   scoped_ptr<NestedDispatcherController> nested_dispatcher_controller_;
 
@@ skipping 73 matching lines @@
 
   // Used by ash/shell.
   content::BrowserContext* browser_context_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_