Set the bound XFB to 0 when it is deleted BUG=605775 Change-Id: Ie7af2c0dc4536b26473510a80955f4628ea496bb Reviewed-on: https://chromium-review.googlesource.com/340113 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org>