Google recently added a flag option to enable webpage translation for alpha languages. This had to be enabled manually by the user.
The company is now turning this option on by default. Alpha languages are languages which do not have a fully developed translation engine on Google Translate. Hence the quality of translation is not as good as regular languages supported by the service.
Google marks these languages as alpha:
Azerbaijani, Bengali, Cebuano, Basque, Gujarati, Hmong, Haitian Creole, Armenian, Javanese, Georgian, Khmer, Kannada, Latin, Lao, Marathi, Tamil, Telugu and Urdu.