mus: Implement ScreenMus::GetCursorScreenPoint().

components/mus/ws/window_tree.h

Index: components/mus/ws/window_tree.h
diff --git a/components/mus/ws/window_tree.h b/components/mus/ws/window_tree.h
index ab8e62430d50ff6c05aee7172d83ae7ed5f9990c..22a3b90ee000fa31f55d25dd155ec3c760b0102c 100644
--- a/components/mus/ws/window_tree.h
+++ b/components/mus/ws/window_tree.h
@@ -23,10 +23,12 @@
 #include "components/mus/ws/user_id.h"
 #include "components/mus/ws/window_tree_binding.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
+#include "ui/gfx/geometry/point.h"
 
 namespace gfx {
 class Insets;
 class Rect;
+class Point;
 }
 
 namespace ui {
@@ -374,6 +376,8 @@ class WindowTree : public mojom::WindowTree,
   void GetWindowManagerClient(
       mojo::AssociatedInterfaceRequest<mojom::WindowManagerClient> internal)
       override;
+  void GetCursorScreenPoint(const GetCursorScreenPointCallback& callback)
+      override;
 
   // mojom::WindowManagerClient:
   void AddAccelerator(uint32_t id,