If the image needs to be redefined with mips, level 0 was copied to a buffer which was then copied to the new image. This change instead stages the old image directly for copy to the new image. Bug: angleproject:4551 Change-Id: I7625f140ddadde0a2b439c5e91c519ad49ae2fd7 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2257264Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
