Merged r13428 into 3.15 branch.

Fix test harness to accept camel-case modes.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/12017013

git-svn-id: https://v8.googlecode.com/svn/branches/3.15@13432 ce2b1a6d-e550-0410-aec6-3dcde31c8c00