ServiceWorker: Test for (un)registering overly long URLs

Regression test for http://crrev.com/278850 to ensure that promises are
rejected when URLs won't make it across IPC.

BUG=386724
R=dominicc@chromium.org

Review URL: https://codereview.chromium.org/363763002

git-svn-id: svn://svn.chromium.org/blink/trunk@177620 bbb929c8-8fbe-4397-9dbb-9b2b20218538