SDL/OPENGL: Add ability to switch between SDL and OpenGL graphics managers.

OSystem_SDL will create a merged list of all graphics modes from SDL and OpenGL. When the user changes the graphics mode in options and restarts ScummVM should switch to that graphics mode in the corresponding graphics manager.

svn-id: r51493

backends/graphics/sdl/sdl-graphics.cpp

@@ -240,6 +240,10 @@ bool SdlGraphicsManager::getFeatureState(OSystem::Feature f) {
 	}
 }
 
+const OSystem::GraphicsMode *SdlGraphicsManager::supportedGraphicsModes() {
+	return s_supportedGraphicsModes;
+}
+
 const OSystem::GraphicsMode *SdlGraphicsManager::getSupportedGraphicsModes() const {
 	return s_supportedGraphicsModes;
 }