mus: Implement ScreenMus::GetCursorScreenPoint().

ui/views/mus/screen_mus_delegate.h

Index: ui/views/mus/screen_mus_delegate.h
diff --git a/ui/views/mus/screen_mus_delegate.h b/ui/views/mus/screen_mus_delegate.h
index 4c7940088c5c04a1e56e2cb57510699e2cd9bfc8..1db1b67faaa3f24d1d5be1592e9ba8e98851ff9c 100644
--- a/ui/views/mus/screen_mus_delegate.h
+++ b/ui/views/mus/screen_mus_delegate.h
@@ -7,6 +7,10 @@
 
 #include "ui/views/mus/mus_export.h"
 
+namespace gfx {
+class Point;
+}
+
 namespace views {
 
 // Screen implementation backed by mus::mojom::DisplayManager.
@@ -14,7 +18,9 @@ class VIEWS_MUS_EXPORT ScreenMusDelegate {
  public:
   virtual void OnWindowManagerFrameValuesChanged() = 0;
 
- protected:
+  virtual gfx::Point GetCursorScreenPoint() = 0;
+
+protected:
   virtual ~ScreenMusDelegate() {}
 };