It is intended to bring memory usage down on idle notifications.

R=erik.corry@gmail.com
BUG=v8:1726

Review URL: https://chromiumcodereview.appspot.com/9323079

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10616 ce2b1a6d-e550-0410-aec6-3dcde31c8c00