Revert revisions 7644 and 7632, they are causing assertion failures in interactive_ui_tests debug mode.
Review URL: http://codereview.chromium.org/6873076

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7664 ce2b1a6d-e550-0410-aec6-3dcde31c8c00