Add non-system-border option on Windows

Sine Striker

2023-12-22 c837319767bb609c6ec806336e49a347c77b11d3

 src/core/style/styleagent_p.h

@@ -26,10 +26,10 @@

        StyleAgent *q_ptr;

        StyleAgent::SystemTheme systemTheme = StyleAgent::Dark;
        StyleAgent::SystemTheme systemTheme = StyleAgent::Unknown;

        virtual void setupSystemThemeHook();
        virtual void removeSystemThemeHook();
        void setupSystemThemeHook();
        void removeSystemThemeHook();

        void notifyThemeChanged(StyleAgent::SystemTheme theme);
    };