Revert r17018 - "Turn on handle zapping for release builds"

BUG=none
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/26457002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17152 ce2b1a6d-e550-0410-aec6-3dcde31c8c00