Add a script to print out tests in the order they were run on each worker.

Read in the stats.json file that run-webkit-tests spits out and print
out a list like:
worker/number:
test1
test2

worker/number
test3
test4

This is useful for being able to diagnose test ordering bugs.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/19920002

git-svn-id: svn://svn.chromium.org/blink/trunk@154672 bbb929c8-8fbe-4397-9dbb-9b2b20218538