mus: Implement ScreenMus::GetCursorScreenPoint().

components/mus/ws/user_display_manager.cc

Index: components/mus/ws/user_display_manager.cc
diff --git a/components/mus/ws/user_display_manager.cc b/components/mus/ws/user_display_manager.cc
index e54e9b7fc444c6813b186f2c49f3824770563253..52fa97b508d08e23183377df185ecd1748c457a5 100644
--- a/components/mus/ws/user_display_manager.cc
+++ b/components/mus/ws/user_display_manager.cc
@@ -7,6 +7,7 @@
 #include "components/mus/ws/display.h"
 #include "components/mus/ws/display_manager.h"
 #include "components/mus/ws/window_manager_state.h"
+#include "mojo/converters/geometry/geometry_type_converters.h"
 
 namespace mus {
 namespace ws {
@@ -62,6 +63,11 @@ void UserDisplayManager::OnWillDestroyDisplay(Display* display) {
     test_observer_->OnDisplayRemoved(display->id());
 }
 
+void UserDisplayManager::OnMouseCursorLocationChanged(
+    const gfx::Point& location) {
+  mouse_location_ = location;
+}
+
 std::set<const WindowManagerState*>
 UserDisplayManager::GetWindowManagerStatesForUser() const {
   std::set<const WindowManagerState*> result;
@@ -120,5 +126,10 @@ void UserDisplayManager::AddObserver(
   OnObserverAdded(observer_impl);
 }
 
+void UserDisplayManager::GetCursorScreenPoint(
+    const GetCursorScreenPointCallback& callback) {
+  callback.Run(mojo::Point::From(mouse_location_));
+}
+
 }  // namespace ws
 }  // namespace mus