In addition, this CL introduces a tiny new helper, which will come in handy later,
plus some minor cleanup.

Review URL: https://chromiumcodereview.appspot.com/9600013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10918 ce2b1a6d-e550-0410-aec6-3dcde31c8c00