Reference/release both the image and parent texture.

BUG=18381089

Change-Id: I379deb9a80eef4cc75082a58bfd14e588d7a93a1
Reviewed-on: https://swiftshader-review.googlesource.com/1410
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>