Currently WebsiteDataStore::defaultAlternativeServicesDirectory and WebsiteDataStore::defaultJavaScriptConfigurationDirectory are unimplemented. It's hard to know they exist because they're in the base WebsiteDataStore.cpp, not in the platform-specific files. I'm not sure what these are for, but likely we need to implement them:

 * WebsiteDataStoreGLib.cpp and WebsiteDataStoreWin.cpp need real implementations (should be done at the same time, only thinking required is what to name the directory)
 * WebsiteDataStorePlayStation.cpp needs a stub implementation that returns an empty string

However, it may be that we don't need to implement if these features are somehow platform-specific. I don't know.