This test creates a predictable 256x256 pattern in an FBO (i.e. x-axis is red and y-axis is green), and then uses glBlitFramebuffer() to blit all or different halves of that FBO to the default framebuffer (i.e. the Vulkan swapchain). When run on a rotated Android device, the predictable pattern helps to determine if/how anything is wrong. Bug: b/158337857 Change-Id: I858964fcb34b8ee5fbdbeade0e1dacaafaea7fa3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2236994Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Ian Elliott <ianelliott@google.com> Commit-Queue: Ian Elliott <ianelliott@google.com>