Repair ChangeLog after script failure in push-to-trunk.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/201923002

git-svn-id: https://v8.googlecode.com/svn/trunk@20002 ce2b1a6d-e550-0410-aec6-3dcde31c8c00