demos: Cube barrier changes from GH #1033
demos: Cube barrier changes from GH #1033

Change-Id: Ib6638235ccf006e962ea3bacac82fdc1a75e08e4

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools