15 hour layover

First and the most important detail is that your itinerary is eligible for 24 hour visa free transit and you don't need any kind of visa. To be allowed to exit the airport, you will have to apply for a temporary entry permit at 24 hour visa free transit as soon as you land in Shanghai. This application is free. You are advised to book your accommodation if your layover is during the night hours and to bring a confirmation printout with you. Also, it is a very good idea to tell to the authorities that you will visit Shanghai Disneyland. Your chances to be granted a temporary entry permit are really very good, but you have to be aware that the issuing of this permit depends on sovereign discretion of immigration authorities.