mus: Implement Window Server Capture

components/mus/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_DISPLAY_MANAGER_DELEGATE_H_
 #define COMPONENTS_MUS_DISPLAY_MANAGER_DELEGATE_H_
 
 #include "components/mus/public/interfaces/view_tree.mojom.h"
 
 namespace mus {
 
 class ServerView;
 
 // A DisplayManagerDelegate an interface to be implemented by an object that
 // manages the lifetime of a DisplayManager, forwards events to the appropriate
 // views, and responses to changes in viewport size.
 class DisplayManagerDelegate {
  public:
   // Returns the root view of this display.
   virtual ServerView* GetRootView() = 0;
 
   // Called when the window managed by the DisplayManager is closed.
   virtual void OnDisplayClosed() = 0;
 
   // Called when an event arrives.
   virtual void OnEvent(mojo::EventPtr event) = 0;
 
+  // Called when the Display loses capture.
+  virtual void OnLostCapture() = 0;
+
   // Signals that the metrics of this display's viewport has changed.
   virtual void OnViewportMetricsChanged(
       const mojo::ViewportMetrics& old_metrics,
       const mojo::ViewportMetrics& new_metrics) = 0;
 
  protected:
   virtual ~DisplayManagerDelegate() {}
 };
 
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_DISPLAY_MANAGER_DELEGATE_H_