Port r21535(8bb4c2b)

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/302453011

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21550 ce2b1a6d-e550-0410-aec6-3dcde31c8c00