Mark editing/selection/4960116.html for auto rebaseline.

Needed after
http://src.chromium.org/viewvc/blink?revision=166551&view=revision

TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/154153006

git-svn-id: svn://svn.chromium.org/blink/trunk@166561 bbb929c8-8fbe-4397-9dbb-9b2b20218538