This is essentially part of https://chromiumcodereview.appspot.com/10825012/
Landing it separately so I can run trybots for the mentioned patch.

TEST=none
BUG=none

Review URL: https://chromiumcodereview.appspot.com/10827383

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151919 0039d316-1c4b-4281-b951-d872f2087c98