mus+ash: Copy parts of ScreenAsh to ScreenMus.

ash/mus/screen_mus.h

 // Copyright 2016 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_MUS_SCREEN_MUS_H_
 #define ASH_MUS_SCREEN_MUS_H_
 
 #include "base/macros.h"
 #include "ui/display/screen_base.h"
 
@@ skipping 16 matching lines @@
   explicit ScreenMus(display::mojom::DisplayController* display_controller);
   ~ScreenMus() override;
 
   // Sets the work area of the display containing |window|.
   void SetWorkAreaInsets(aura::Window* window, const gfx::Insets& insets);
 
  private:
   // display::ScreenBase:
   display::Display GetDisplayNearestWindow(aura::Window* window) const override;
   gfx::Point GetCursorScreenPoint() override;
+  bool IsWindowUnderCursor(gfx::NativeWindow window) override;
+  gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) override;
 
   display::mojom::DisplayController* display_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenMus);
 };
 
 }  // namespace ash
 
 #endif  // ASH_MUS_SCREEN_MUS_H_