Delete mus surfaces hit testing

components/mus/ws/display.h

 // Copyright 2015 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 COMPONENTS_MUS_WS_DISPLAY_H_
 #define COMPONENTS_MUS_WS_DISPLAY_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 147 matching lines @@
       WindowManagerFactoryService* service);
 
   // PlatformDisplayDelegate:
   ServerWindow* GetRootWindow() override;
   void OnEvent(const ui::Event& event) override;
   void OnNativeCaptureLost() override;
   void OnDisplayClosed() override;
   void OnViewportMetricsChanged(
       const mojom::ViewportMetrics& old_metrics,
       const mojom::ViewportMetrics& new_metrics) override;
-  void OnTopLevelSurfaceChanged(cc::SurfaceId surface_id) override;
   void OnCompositorFrameDrawn() override;
 
   // FocusControllerDelegate:
   bool CanHaveActiveChildren(ServerWindow* window) const override;
 
   // FocusControllerObserver:
   void OnActivationChanged(ServerWindow* old_active_window,
                            ServerWindow* new_active_window) override;
   void OnFocusChanged(FocusControllerChangeSource change_source,
                       ServerWindow* old_focused_window,
@@ skipping 24 matching lines @@
   int32_t last_cursor_;
 
   ServerWindowTracker activation_parents_;
 
   // Set of windows with surfaces that need to be destroyed once the frame
   // draws.
   std::set<ServerWindow*> windows_needing_frame_destruction_;
 
   WindowManagerStateMap window_manager_state_map_;
 
-  cc::SurfaceId top_level_surface_id_;
-
   DISALLOW_COPY_AND_ASSIGN(Display);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_DISPLAY_H_