Photo: Gabrielle Lurie Gabrielle Lurie, Special To The Chronicle Image 1of/21 CaptionClose Image 1 of 21 Tonga Room950 Mason St.Dreamforce guidebook quote: "Rather than being a place to impress your guests, it’s a good informal place to get to know your fellow attendees and build relationships." Tonga Room 950 Mason St. Dreamforce guidebook quote:...