mus: Implement ScreenMus::GetCursorScreenPoint().

components/mus/ws/user_display_manager.h

Index: components/mus/ws/user_display_manager.h
diff --git a/components/mus/ws/user_display_manager.h b/components/mus/ws/user_display_manager.h
index c17a7c6981a155821d53159ac3482e8ddaedc8ad..812d36d2bd6d046d83eb73453e09a18c778f7921 100644
--- a/components/mus/ws/user_display_manager.h
+++ b/components/mus/ws/user_display_manager.h
@@ -12,6 +12,7 @@
 #include "components/mus/ws/user_id.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/public/cpp/bindings/interface_ptr_set.h"
+#include "ui/gfx/geometry/point.h"
 
 namespace mus {
 namespace ws {
@@ -31,6 +32,8 @@ class UserDisplayManager : public mojom::DisplayManager {
                      const UserId& user_id);
   ~UserDisplayManager() override;
 
+  gfx::Point cursor_location() { return cursor_location_; }
+
   void OnFrameDecorationValuesChanged(WindowManagerState* wms);
 
   void AddDisplayManagerBinding(
@@ -39,6 +42,9 @@ class UserDisplayManager : public mojom::DisplayManager {
   // Called by Display prior to |display| being removed and destroyed.
   void OnWillDestroyDisplay(Display* display);
 
+  // Updates the location of the cursor on this user's display.
+  void OnMouseCursorLocationChanged(const gfx::Point& location);
+
  private:
   friend class test::UserDisplayManagerTestApi;
 
@@ -71,6 +77,8 @@ class UserDisplayManager : public mojom::DisplayManager {
   mojo::InterfacePtrSet<mojom::DisplayManagerObserver>
       display_manager_observers_;
 
+  gfx::Point cursor_location_;
+
   // Observer used for tests.
   mojom::DisplayManagerObserver* test_observer_ = nullptr;