ensure that what is valid for a surface is also valid for an image

Note, this change will cause some previously succeeding surfaces to fail to build (since they could not snap their image)

Bug: skia:7598
Change-Id: I012ca752ba1351a904625d216429eab646ca4a85
Reviewed-on: https://skia-review.googlesource.com/105421
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
4 files changed