Fix "modal isn't modal in multi displays" issue

ash/root_window_controller.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_ROOT_WINDOW_CONTROLLER_H_
 #define ASH_ROOT_WINDOW_CONTROLLER_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 150 matching lines @@
   // Returns the system tray on this root window. Note that
   // calling this on the root window that doesn't have a shelf will
   // lead to a crash.
   SystemTray* GetSystemTray();
 
   // Shows context menu at the |location_in_screen|. This uses
   // |ShellDelegate::CreateContextMenu| to define the content of the menu.
   void ShowContextMenu(const gfx::Point& location_in_screen,
                        ui::MenuSourceType source_type);
 
+  // True if the window can receive events on this root window.
+  bool CanWindowReceiveEvents(aura::Window* window);
+
   // Returns the layout-manager for the appropriate modal-container. If the
   // window is inside the lockscreen modal container, then the layout manager
   // for that is returned. Otherwise the layout manager for the default modal
   // container is returned.
   // If no window is specified (i.e. |window| is NULL), then the lockscreen
   // modal container is used if the screen is currently locked. Otherwise, the
   // default modal container is used.
   SystemModalContainerLayoutManager* GetSystemModalLayoutManager(
       aura::Window* window);
 
@@ skipping 153 matching lines @@
 
 // On classic ash, returns the RootWindowController for the given |root_window|.
 // On mus ash, returns the RootWindowController for the primary display.
 // See RootWindowController class comment above.
 ASH_EXPORT RootWindowController* GetRootWindowController(
     const aura::Window* root_window);
 
 }  // namespace ash
 
 #endif  // ASH_ROOT_WINDOW_CONTROLLER_H_