Port of r10540.

R=yangguo@chromium.org
TEST=mjsunit/debug-stepout-scope

Review URL: https://chromiumcodereview.appspot.com/9225055

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10547 ce2b1a6d-e550-0410-aec6-3dcde31c8c00