mus Window Server: implement event capture

components/mus/ws/display_manager_delegate.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_MANAGER_DELEGATE_H_
 #define COMPONENTS_MUS_WS_DISPLAY_MANAGER_DELEGATE_H_
 
 #include "components/mus/public/interfaces/window_tree.mojom.h"
 #include "components/mus/ws/ids.h"
 
@@ skipping 18 matching lines @@
  public:
   // Returns the root window of this display.
   virtual ServerWindow* GetRootWindow() = 0;
 
   // Called when the window managed by the DisplayManager is closed.
   virtual void OnDisplayClosed() = 0;
 
   // Called when an event arrives.
   virtual void OnEvent(const ui::Event& event) = 0;
 
+  // Called when the Display loses capture.
+  virtual void OnNativeCaptureLost() = 0;
+
   // Signals that the metrics of this display's viewport has changed.
   virtual void OnViewportMetricsChanged(
       const mojom::ViewportMetrics& old_metrics,
       const mojom::ViewportMetrics& new_metrics) = 0;
 
   virtual void OnTopLevelSurfaceChanged(cc::SurfaceId surface_id) = 0;
 
   // Called when a compositor frame is finished drawing.
   virtual void OnCompositorFrameDrawn() = 0;
 
  protected:
   virtual ~DisplayManagerDelegate() {}
 };
 
 }  // namespace ws
 
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_DISPLAY_MANAGER_DELEGATE_H_