Merged r15848, r15849 into trunk branch.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/19726011

git-svn-id: https://v8.googlecode.com/svn/trunk@15850 ce2b1a6d-e550-0410-aec6-3dcde31c8c00