GameSettings: Add a bunch more user settings

src/duckstation-qt/qtutils.h

@@ -9,6 +9,7 @@ Q_DECLARE_METATYPE(std::optional<bool>);
 
 class ByteStream;
 
+class QComboBox;
 class QFrame;
 class QKeyEvent;
 class QTableView;
@@ -54,4 +55,7 @@ void OpenURL(QWidget* parent, const QUrl& qurl);
 /// Opens a URL string with the default handler.
 void OpenURL(QWidget* parent, const char* url);
 
+/// Fills a combo box with resolution scale options.
+void FillComboBoxWithResolutionScales(QComboBox* cb);
+
 } // namespace QtUtils