Fix redrawing of SkiaDisplay on Windows (now the cursor overlay is visible)

src/she/skia/skia_display.cpp

@@ -90,7 +90,7 @@ bool SkiaDisplay::flip()
     return false;
   }
 
-  m_window.invalidate();
+  m_window.updateWindow();
   return true;
 }
 

src/she/win/window.h

@@ -148,8 +148,9 @@ namespace she {
       m_hcursor = hcursor;
     }
 
-    void invalidate() {
+    void updateWindow() {
       InvalidateRect(m_hwnd, NULL, FALSE);
+      UpdateWindow(m_hwnd);
     }
 
     HWND handle() {