swapchain buffer count increased to 2 for wp8.x
swapchain buffer count increased to 2 for wp8.x

MSOpenTech/angle-win8.0,MSOpenTech/angle-win8.0,MSOpenTech/angle-win8.0,stammen/angleproject,MSOpenTech/angle-win8.0,stammen/angleproject,stammen/angleproject,stammen/angleproject