A source tells me Naples Ristorante e Pizzeria in Westfield Montgomery Mall in Bethesda will close permanently at the close of business Saturday night. The closure is one of many in the mall's new Dining Terrace over the last year, but perhaps the biggest blow yet, after that of Met Bethesda upstairs. Both restaurants were brought in to anchor the new, upscale dining area.Met Bethesda had visibility issues being tucked away on an upper floor, but Naples had prime real estate and an exterior entrance. The mall still has its biggest dining draw, The Cheesecake Factory, and another large restaurant tenant that was part of the multimillion dollar relaunch of the mall, CRAVE. Taking the mall upscale also included the opening of a 16-screen ArcLight Cinemas theater.It will be interesting to see what Westfield does with these two large restaurant spaces - bring in even-heavier-hitting brands and chefs, or convert them to smaller or other uses.