Settings: Expose Save() method to interface

src/core/settings.h

@@ -11,6 +11,7 @@ class SettingsInterface
 public:
   virtual ~SettingsInterface();
 
+  virtual bool Save() = 0;
   virtual void Clear() = 0;
 
   virtual int GetIntValue(const char* section, const char* key, int default_value = 0) = 0;

src/frontend-common/ini_settings_interface.h

@@ -13,7 +13,7 @@ public:
   INISettingsInterface(std::string filename);
   ~INISettingsInterface() override;
 
-  bool Save();
+  bool Save() override;
 
   void Clear() override;