Available in Chrome 40+
This sample demonstrates basic service worker registration, with the service worker's fetch handler
not taking any special action for most requests. However, there is special behavior if a request
is made to the Google URL Shortener API
and a custom request header is set, X-Mock-Response. (There's no special significance
to this name; any convention that both the controlled page and the service worker agree on could be used.)
Instead of returning actual responses for those API requests, the service worker will return mock response
that should appear identical to a real API response from the perspective of this controlled page.
Visit chrome://inspect/#service-workers and click on the "inspect" link below
the registered service worker to view logging statements for the various actions the
service-worker.js script is performing.