Port r9937 (c263a9e).

BUG=
TEST=

Review URL: http://codereview.chromium.org/8509015
Patch from Gergely Kis <gergely@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9946 ce2b1a6d-e550-0410-aec6-3dcde31c8c00