Remove destructors from ScriptWrappable objects in modules/

R=haraken@chromium.org
BUG=340522

Review URL: https://codereview.chromium.org/367113005

git-svn-id: svn://svn.chromium.org/blink/trunk@179446 bbb929c8-8fbe-4397-9dbb-9b2b20218538