Update webkitpy code to use google cloud storage for test results.

(This includes changes to the garden-o-matic javascript as well).

This patch should not land until crbug.com/261749 and crbug.com/261742
are fixed and live.

R=abarth@chromium.org
BUG=261753

Review URL: https://codereview.chromium.org/19549008

git-svn-id: svn://svn.chromium.org/blink/trunk@157249 bbb929c8-8fbe-4397-9dbb-9b2b20218538