Don't discard the storage on forceRelease, simply mark the image as dirty. It was overkill to always destroy the storage, especially for cube maps. Instead, just make sure the image thinks it's dirty when robust resource init is enabled so that it is always copied to the storage after redefinition. BUG=angleproject:1635 Change-Id: Ieba065d1873ca66a216bd05f4f8afa9c75349ff9 Reviewed-on: https://chromium-review.googlesource.com/526295 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>