mus: Implement ScreenMus::GetCursorScreenPoint().

components/mus/ws/window_manager_state.cc

Index: components/mus/ws/window_manager_state.cc
diff --git a/components/mus/ws/window_manager_state.cc b/components/mus/ws/window_manager_state.cc
index 7fc9bd2556f0b80562c7b4eb5b9c1fa5fef1e4a4..681a52345687cd9536817f4c5dbb4ef4d18303b6 100644
--- a/components/mus/ws/window_manager_state.cc
+++ b/components/mus/ws/window_manager_state.cc
@@ -369,6 +369,11 @@ void WindowManagerState::OnServerWindowCaptureLost(ServerWindow* window) {
   window_server()->ProcessLostCapture(window);
 }
 
+void WindowManagerState::OnMouseCursorLocationChanged(const gfx::Point& point) {
+  window_server()->display_manager()->GetUserDisplayManager(user_id_)->
+      OnMouseCursorLocationChanged(point);
+}
+
 void WindowManagerState::DispatchInputEventToWindow(ServerWindow* target,
                                                     bool in_nonclient_area,
                                                     const ui::Event& event,