Patch by Peter Varga.

BUG=none
TEST=cctest/test-api/PropertyEnumeration

Review URL: http://codereview.chromium.org/7129058

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8264 ce2b1a6d-e550-0410-aec6-3dcde31c8c00