Layout test to ensure we bypass ServiceWorkers for synchronous resource loads to avoid deadlocks when the worker and page are running in the same process.

[1] https://codereview.chromium.org/553333005/
[2] this cl

BUG=413103

Review URL: https://codereview.chromium.org/573293005

git-svn-id: svn://svn.chromium.org/blink/trunk@182888 bbb929c8-8fbe-4397-9dbb-9b2b20218538