history_reload.html sometimes fails with MISSING.

BUG=311301
TBR=pilgrim@chromium.org

Review URL: https://codereview.chromium.org/376843003

git-svn-id: svn://svn.chromium.org/blink/trunk@177645 bbb929c8-8fbe-4397-9dbb-9b2b20218538