LiveObjectList functionality.

Patch by Mark Lam from Hewlett-Packard Development Company, LP

Review URL: http://codereview.chromium.org/6351007


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7011 ce2b1a6d-e550-0410-aec6-3dcde31c8c00