Update the name of the layout test helper binaries and remove dead code

R=alph@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/130553004

git-svn-id: svn://svn.chromium.org/blink/trunk@164967 bbb929c8-8fbe-4397-9dbb-9b2b20218538