Fix GardeningServer/scripts/ui_unittests.js

This testing framework is horrible.  When you have a syntax error
you have to go digging in the console to fine it, it doesn't notice.

BUG=389681
R=abarth@chromium.org, abarth

Review URL: https://codereview.chromium.org/359813002

git-svn-id: svn://svn.chromium.org/blink/trunk@177145 bbb929c8-8fbe-4397-9dbb-9b2b20218538