Hacky first-pass implementation of garden-o-matic.appspot

The unittests don't all pass yet.

R=abarth@chromium.org, ojan@chromium.org

Review URL: https://codereview.chromium.org/25363002

git-svn-id: svn://svn.chromium.org/blink/trunk@158548 bbb929c8-8fbe-4397-9dbb-9b2b20218538