Vulkan: Set the Vulkan scissor to the GLES viewport Some Vulkan drivers are not clipping rendering that is outside of the viewport, and the Vulkan spec has some language that indicates that ANGLE should set the scissor: The application must ensure (using scissor if necessary) that all rendering is contained within the render area. In this case, ANGLE is "the application". Bug: angleproject:3253 Bug: angleproject:3254 Change-Id: I6885a3aa6daed57f6ae1c3d974663d763cad10c9 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1553973 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Ian Elliott <ianelliott@google.com>