Change CaptureSynchronizer and PointerWatcherEventRouter to support multiple CaptureClients.

ui/aura/mus/window_tree_client.h

 // Copyright 2014 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 UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 #define UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 148 matching lines @@
   // whether the move loop completed successfully.
   void PerformWindowMove(Window* window,
                          ui::mojom::MoveLoopSource source,
                          const gfx::Point& cursor_location,
                          const base::Callback<void(bool)>& callback);
 
   // Cancels a in progress window move. (If no window is currently being moved,
   // does nothing.)
   void CancelWindowMove(Window* window);
 
+  // Called when the capture client has been set for a window.
+  void OnCaptureClientSet(client::CaptureClient* capture_client);
+
+  // Called when the capture client will be unset for a window.
+  void OnCaptureClientUnset(client::CaptureClient* capture_client);
+
   void AddObserver(WindowTreeClientObserver* observer);
   void RemoveObserver(WindowTreeClientObserver* observer);
 
   void AddTestObserver(WindowTreeClientTestObserver* observer);
   void RemoveTestObserver(WindowTreeClientTestObserver* observer);
 
  private:
   friend class InFlightBoundsChange;
   friend class InFlightFocusChange;
   friend class InFlightPropertyChange;
@@ skipping 366 matching lines @@
   std::unique_ptr<ui::Gpu> gpu_;
   std::unique_ptr<MusContextFactory> compositor_context_factory_;
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_TREE_CLIENT_H_