Ported r8315 (d70d395).

BUG=
TEST=

Review URL: http://codereview.chromium.org//7216004
Patch from Paul Lind <plind44@gmail.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8340 ce2b1a6d-e550-0410-aec6-3dcde31c8c00