mus: Implement Window Server Capture

components/mus/ws/window_tree_impl.h

Index: components/mus/ws/window_tree_impl.h
diff --git a/components/mus/ws/window_tree_impl.h b/components/mus/ws/window_tree_impl.h
index 38f71fa568bb078c6c3738eb4567fed713f3947e..7b96a650b73b30ae49bc3ecc136e1bfde5115d6f 100644
--- a/components/mus/ws/window_tree_impl.h
+++ b/components/mus/ws/window_tree_impl.h
@@ -121,6 +121,7 @@ class WindowTreeImpl : public mojom::WindowTree, public AccessPolicyDelegate {
                                          bool originated_change);
   void ProcessFocusChanged(const ServerWindow* old_focused_window,
                            const ServerWindow* new_focused_window);
+  void ProcessLostCapture(const ServerWindow* old_lost_capture);
   void ProcessTransientWindowAdded(const ServerWindow* window,
                                    const ServerWindow* transient_window,
                                    bool originated_change);
@@ -212,6 +213,8 @@ class WindowTreeImpl : public mojom::WindowTree, public AccessPolicyDelegate {
       Id window_id,
       const mojo::Callback<void(mojo::Array<mojom::WindowDataPtr>)>& callback)
       override;
+  void SetCapture(uint32_t change_id, Id window_id) override;
+  void ReleaseCapture(uint32_t change_id, Id window_id) override;
   void SetWindowBounds(uint32_t change_id,
                        Id window_id,
                        mojo::RectPtr bounds) override;